chore(deps): update dependency apple/swift-protobuf to v1.31.0

[cgrindel-self-hosted-renovate]

This PR contains the following updates:

Package	Update	Change
apple/swift-protobuf	minor	1.30.0 -> 1.31.0

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Release Notes

apple/swift-protobuf (apple/swift-protobuf)

v1.31.0

Compare Source

What's Changed

SemVer Minor

• use package visibility for an internal helper. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1790
• Create a bytecode interpreter to compactly represent text/JSON name maps. by @​allevato in https://github.com/apple/swift-protobuf/pull/1789
• Mark the legacy _NameMap initializer as deprecated. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1816
• Validate Timestamp before generating JSON to match upstream. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1824
• Validate Duration before generating JSON to match upstream. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1823
• Support "edition2024". by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1825
• Add protoc product by @​FranzBusch in https://github.com/apple/swift-protobuf/pull/1836
• Deprecate another helper. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1841
• Prepare for a 1.31.0 release and update docs by @​FranzBusch in https://github.com/apple/swift-protobuf/pull/1843

SemVer Patch

• As of Swift 5.9 Data was Sendable, so remove @unchecked use. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1787
• Create fewer temporary Strings when computing JSON names. by @​allevato in https://github.com/apple/swift-protobuf/pull/1807
• Prune nameString to reduce runtime size of Name by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1806
• Add automated protoc artifact bundle generation for releases by @​FranzBusch in https://github.com/apple/swift-protobuf/pull/1835
• Improve plugin error handling by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1840

Other Changes

• Use 6.1.2 on CI by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1783
• Now that 5.10 is the baseline, remove some old bits/refs. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1788
• Remove the 5.9 comments. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1786
• Move two of the tests off @testable import by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1785
• Move SwiftProtobufTests to using package visibility. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1791
• Capture known failures. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1799
• One reference missed in the NameMap changes. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1802
• Update proto files from upstream. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1803
• Inline the bytecode string into the _NameMap.init(bytecode:) call. by @​allevato in https://github.com/apple/swift-protobuf/pull/1804
• Enable the blocking of legacy _NameMap support. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1805
• Use unchecked math operations. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1809
• Tweak Protos layout and update proto files by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1810
• Remove the use of lazy, unverified_lazy, and ctype in test files. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1811
• Remove one more place ctype was used that got missed by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1812
• Put a proto package on the test file. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1813
• Support blocking deprecated apis from the runtime. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1814
• Fix copy/paste in comment that has the wrong thing. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1815
• Move the test helpers to package visibility. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1817
• Drop unneeded argument in build dataset. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1819
• Remove import Swift, doesn't seem to be needed. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1820
• Add expected failures for the new conformance test issues. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1822
• Update protos from upstream. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1826
• Per #​1830, tweak the phrasing. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1831
• Bring over the last upstream proto file that was left off last time. by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1832
• Create separate protoc releases by @​FranzBusch in https://github.com/apple/swift-protobuf/pull/1837
• Fix make_latest from Boolean to String by @​FranzBusch in https://github.com/apple/swift-protobuf/pull/1838
• Remove unneeded arguments by @​thomasvl in https://github.com/apple/swift-protobuf/pull/1842

Full Changelog: apple/swift-protobuf@1.30.0...1.31.0

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[cgrindel]

Swift Package Manager Compatibility Issue Found

I've investigated the build failure that occurs when updating to swift-protobuf v1.31.0 and identified the root cause.

Root Cause

Swift-protobuf v1.31.0 introduced a new protoc product as a binaryTarget (PR #1836). However, this triggers a known bug in Swift Package Manager where it incorrectly handles executable products that use binaryTarget.

The Error

When rules_swift_package_manager runs swift package describe --type json, it fails with:

error: executable product 'protoc' expects target 'protoc' to be executable; an executable target requires a 'main.swift' file

This occurs because Swift Package Manager doesn't properly recognize binaryTarget as a valid executable target.

Swift Package Manager Bug

This is documented as Issue #8101 in the Swift Package Manager repository: "Conflicting detection of executable targets when using a binaryTarget on an executable product"

The bug manifests as:

1. SPM complains that the binaryTarget is missing a main.swift file
2. If you add a main.swift, it then complains about having multiple executable targets

Impact on rules_swift_package_manager

Since rules_swift_package_manager depends on swift package describe to analyze package manifests, and this command fails due to the SPM bug, swift-protobuf v1.31.0 is currently incompatible with rules_swift_package_manager.

Next Steps

This update should be blocked until either:

1. Swift Package Manager fixes issue #8101, or
2. rules_swift_package_manager implements a workaround for this specific case, or
3. Swift-protobuf modifies their approach for the protoc target

Testing Details

• Tried updating swift-tools-version from 5.7 → 5.8 → 5.10 → 6.0 → 6.1
• All versions exhibit the same failure
• The issue is not with our configuration but with the upstream SPM bug

The grpc_example demonstrates this issue when attempting to build after the update.