Tests

Fix TypeIs narrowing before isinstance #22552

Job	Run time
Test mypyc suite with 32-bit Python	1h 0m 15s
Test suite with py314-windows-64	27m 19s
Type check our own code (py310-ubuntu)	1m 4s
Test suite with py312-ubuntu	10m 4s
Test suite with py313-ubuntu, mypyc-compiled	16m 7s
mypyc runtime tests with py313-macos	6m 15s
Type check our own code (py310-windows-64)	2m 31s
Test suite with py314-ubuntu, mypyc-compiled	15m 36s
mypyc runtime tests with py310-ubuntu	7m 12s
Test suite with py314t-ubuntu, mypyc-compiled	17m 46s
Parallel tests with py314-ubuntu, interpreted	25m 43s
Parallel tests with py314-ubuntu, mypyc-compiled	28m 40s
Test suite with py310-ubuntu, mypyc-compiled	17m 9s
Test suite with py315-ubuntu, mypyc-compiled	16m 7s
Test suite with py311-ubuntu	9m 32s
Formatting and code style with Black + ruff	1m 41s
Parallel tests with py314-windows-64, interpreted	11m 31s
	4h 34m 32s

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