ci(conformance): pin harness to 0.2.0-alpha.3 with expected-failures baseline #2702

Job	Run time
checks / readme-snippets	13s
checks / pre-commit	31s
checks / test (3.12, locked, ubuntu-latest)	58s
checks / test (3.10, locked, windows-latest)	1m 43s
checks / test (3.10, lowest-direct, ubuntu-latest)	1m 14s
checks / test (3.11, lowest-direct, ubuntu-latest)	1m 23s
checks / test (3.11, lowest-direct, windows-latest)	1m 42s
checks / test (3.10, locked, ubuntu-latest)	55s
checks / test (3.12, lowest-direct, ubuntu-latest)	1m 19s
checks / test (3.12, lowest-direct, windows-latest)	1m 57s
checks / test (3.12, locked, windows-latest)	1m 20s
checks / test (3.13, locked, ubuntu-latest)	49s
checks / test (3.13, lowest-direct, windows-latest)	1m 54s
checks / test (3.13, locked, windows-latest)	1m 30s
checks / test (3.11, locked, windows-latest)	1m 32s
checks / test (3.13, lowest-direct, ubuntu-latest)	1m 3s
checks / test (3.11, locked, ubuntu-latest)	53s
checks / test (3.14, locked, windows-latest)	2m 30s
checks / test (3.10, lowest-direct, windows-latest)	1m 25s
checks / test (3.14, lowest-direct, windows-latest)	1m 40s
checks / test (3.14, locked, ubuntu-latest)	2m 0s
checks / test (3.14, lowest-direct, ubuntu-latest)	1m 2s
all-green	4s
	29m 37s

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