Add `ReadOnly` support for TypedDicts #13306

Job	Run time
Test mypyc suite with 32-bit Python	6m 42s
Test suite with py38-ubuntu, mypyc-compiled	17m 27s
Test suite with py38-windows-64	19m 55s
Test suite with py39-ubuntu	17m 18s
Test suite with py310-ubuntu	16m 7s
Test suite with py311-ubuntu, mypyc-compiled	15m 53s
Test suite with py312-ubuntu, mypyc-compiled	19m 18s
Test suit with py313-dev-ubuntu, mypyc-compiled	19m 35s
mypyc runtime tests with py39-macos	6m 51s
mypyc runtime tests with py38-debug-build-ubuntu	4m 2s
Type check our own code (py38-ubuntu)	1m 49s
Type check our own code (py38-windows-64)	2m 19s
Formatting and code style with Black + ruff	37s
	2h 27m 53s

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