Disallow `TypeVar` constraints parameterized by type variables #13969

Job	Run time
Test mypyc suite with 32-bit Python	7m 20s
Test suite with py38-ubuntu, mypyc-compiled	18m 34s
Test suite with py38-windows-64	19m 48s
Test suite with py39-ubuntu	17m 30s
Test suite with py310-ubuntu	16m 49s
Test suite with py311-ubuntu, mypyc-compiled	15m 52s
Test suite with py312-ubuntu, mypyc-compiled	18m 48s
Test suite with py313-ubuntu, mypyc-compiled	18m 23s
mypyc runtime tests with py39-macos	6m 23s
Type check our own code (py38-ubuntu)	2m 9s
Type check our own code (py38-windows-64)	2m 37s
Formatting and code style with Black + ruff	1m 42s
	2h 25m 55s

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