[PEP 695] Enable new type parameter syntax by default #13203

Job	Run time
Test mypyc suite with 32-bit Python	6m 53s
Test suite with py38-ubuntu, mypyc-compiled	18m 54s
Test suite with py38-windows-64	19m 55s
Test suite with Python nightly	14m 14s
Test suite with py39-ubuntu	18m 10s
Test suite with py310-ubuntu	15m 49s
Test suite with py311-ubuntu, mypyc-compiled	15m 53s
Test suite with py312-ubuntu, mypyc-compiled	17m 59s
mypyc runtime tests with py39-macos	5m 32s
mypyc runtime tests with py38-debug-build-ubuntu	4m 42s
Type check our own code (py38-ubuntu)	1m 50s
Type check our own code (py38-windows-64)	2m 32s
Formatting and code style with Black + ruff	32s
	2h 22m 55s

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