Add LangSmith tracing sample (#292) #1145

Job	Run time
build-lint-test (3.10, macos-intel)	8m 53s
build-lint-test (3.10, macos-arm)	6m 27s
build-lint-test (3.10, windows-latest)	6m 38s
build-lint-test (3.14, ubuntu-latest)	15m 6s
build-lint-test (3.14, windows-latest)	17m 9s
build-lint-test (3.14, macos-intel)	19m 30s
build-lint-test (3.14, macos-arm)	9m 5s
build-lint-test (3.10, ubuntu-latest)	5m 47s
	1h 28m 35s

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