Add workflow to bump Matter SDK dependency

Author: agners

.github/workflows/dependency-update.yaml

@@ -0,0 +1,55 @@
+name: Update Matter SDK submodule
+
+on:
+  schedule:
+    # Runs at 04:30 UTC every day
+    - cron: '04 30 * * *'
+  workflow_dispatch:
+
+permissions:
+  contents: write
+  pull-requests: write
+
+jobs:
+  update-submodule:
+    runs-on: ubuntu-latest
+
+    steps:
+      # Checkout the repository
+      - name: Checkout Repository
+        uses: actions/checkout@v4
+        with:
+          submodules: false
+
+      # Update submodule (not recursive)
+      - name: Update Submodule
+        id: update-submodule
+        run: |
+          short_hash_before=$(cd connectedhomeip && git rev-parse --short HEAD)
+          echo "short_hash_before=${short_hash_before}" > $GITHUB_OUTPUT
+          git submodule update --remote connectedhomeip/
+          git add connectedhomeip/
+          if git diff-index --quiet HEAD; then
+              echo "empty=true" > $GITHUB_OUTPUT
+              exit 0
+          fi
+          short_hash=$(cd connectedhomeip && git rev-parse --short HEAD)
+          echo "short_hash=${short_hash}" > $GITHUB_OUTPUT
+
+      # Create Pull Request only if there were changes
+      - name: Create Pull Request
+        if: ! steps.update-submodule.outputs.empty
+        uses: peter-evans/create-pull-request@v4
+        with:
+          commit-message: Update Matter SDK to `${{steps.update-submodule.outputs.short_hash}}`
+          title: Update Matter SDK to `${{steps.update-submodule.outputs.short_hash}}`
+          body: |
+            Bumps [connectedhomeip](https://github.com/project-chip/connectedhomeip)
+            from `${{steps.update-submodule.outputs.short_hash_before}}` to
+            `${{steps.update-submodule.outputs.short_hash}}`.
+
+            See full diff at
+            https://github.com/project-chip/connectedhomeip/compare/${{steps.update-submodule.outputs.short_hash_before}}...${{steps.update-submodule.outputs.short_hash}}.
+          branch: update-connectedhomeip-submodule-${{ github.run_id }}
+          delete-branch: true
+