Protect against deregistered profile functions in greenlet switches #3410

Job	Run time
Decide which wheel types to build	1s
Build source distribution	16s
macosx_x86_64 wheels	3m 33s
macosx_arm64 wheels	3m 32s
manylinux_x86_64 wheels	3m 32s
musllinux_x86_64 wheels	3m 30s
manylinux_i686 wheels	3m 32s
manylinux_x86_64_manylinux2010_hack wheels	3m 33s
Build and test wheels	1s
upload_pypi	1s
	21m 31s

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