Use protocols instead of `importlib.abc.Loader/MetaPathFinder/PathEntryFinder` #24085

Job	Run time
Run mypy against the stubs (linux, 3.8)	1m 31s
Run mypy against the stubs (linux, 3.9)	1m 41s
Run mypy against the stubs (linux, 3.10)	1m 45s
Run mypy against the stubs (linux, 3.11)	1m 36s
Run mypy against the stubs (linux, 3.12)	1m 45s
Run mypy against the stubs (win32, 3.8)	1m 33s
Test typeshed with pyright (Linux, 3.8)	1m 2s
Run pytype against the stubs	1m 35s
Run mypy against the stubs (win32, 3.9)	1m 42s
Test typeshed with pyright (Linux, 3.9)	57s
Run mypy against the stubs (win32, 3.10)	1m 39s
Test typeshed with pyright (Linux, 3.10)	55s
Run mypy against the stubs (win32, 3.11)	1m 29s
Test typeshed with pyright (Linux, 3.11)	54s
Run mypy on the test cases	3m 16s
Run mypy against the stubs (win32, 3.12)	1m 44s
Test typeshed with pyright (Linux, 3.12)	56s
Run mypy against the stubs (darwin, 3.8)	1m 30s
Test typeshed with pyright (Windows, 3.8)	1m 1s
Run mypy against the stubs (darwin, 3.9)	1m 42s
Test typeshed with pyright (Windows, 3.9)	53s
Run the stub_uploader tests	2m 59s
Run mypy against the stubs (darwin, 3.10)	1m 37s
Test typeshed with pyright (Windows, 3.10)	56s
Run mypy against the stubs (darwin, 3.11)	1m 36s
Test typeshed with pyright (Windows, 3.11)	52s
Check typeshed structure	7s
Run mypy against the stubs (darwin, 3.12)	1m 55s
Test typeshed with pyright (Windows, 3.12)	57s
Test typeshed with pyright (Darwin, 3.8)	56s
Test typeshed with pyright (Darwin, 3.9)	57s
Test typeshed with pyright (Darwin, 3.10)	53s
Test typeshed with pyright (Darwin, 3.11)	55s
Test typeshed with pyright (Darwin, 3.12)	59s
	46m 45s

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