Tests

Bump third_party/libdatachannel/repo from `59ce380` to `7f42c7d` #100629

Job	Run time
REPL Tests - Linux	2h 8m 40s
Test Suites - Darwin (no-ble-no-shell-asan-clang)	1h 28m 10s
Test Suites - Darwin (no-ble-no-shell-tsan-clang)	2h 3m 48s
Test Suites - Linux (no-ble-no-shell-tsan-clang)	1h 51m 3s
REPL Tests - Darwin	0s
	7h 31m 41s

Provide feedback