Correctly narrow types for `tuple[type[X], ...]` (#15691) #10663

Job	Run time
Test suite with py38-ubuntu, mypyc-compiled	22m 9s
Test suite with py38-windows-64	35m 44s
Test suite with py39-ubuntu	29m 6s
Test suite with py310-ubuntu	20m 42s
Test suite with py311-ubuntu, mypyc-compiled	22m 39s
Test suite with py312-ubuntu, mypyc-compiled	22m 48s
mypyc runtime tests with py38-macos	7m 17s
mypyc runtime tests with py38-debug-build-ubuntu	7m 2s
Type check our own code (py38-ubuntu)	1m 56s
Type check our own code (py38-windows-64)	3m 19s
Formatting and code style with Black + ruff	54s
Test mypyc suite with 32-bit Python	10m 38s
	3h 4m 14s

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