Tests

Document MYPY_FORCE_COLOR and FORCE_COLOR in --help #18321

Job	Run time
Test mypyc suite with 32-bit Python	11m 57s
Test suite with py311-ubuntu	8m 0s
Test suite with py310-ubuntu	10m 51s
Test suite with py39-ubuntu, mypyc-compiled	14m 58s
Test suite with py312-ubuntu, mypyc-compiled	13m 38s
Type check our own code (py39-windows-64)	2m 37s
Test suite with py314-dev-ubuntu	17m 7s
Type check our own code (py39-ubuntu)	1m 37s
Test suite with py313-windows-64	24m 11s
mypyc runtime tests with py39-macos	6m 36s
Formatting and code style with Black + ruff	2m 3s
Test suite with py313-ubuntu, mypyc-compiled	14m 11s
	2h 7m 46s

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