[Dev] Add free-threaded wheels to release verification

[lidavidm]

Does it make sense to add 3.14t to release verification too? (python_versions in test_linux_wheels and test_macos_wheels). Maybe putting the PYTHON_GIL=0 detection inside the test scripts instead of being passed in would be good then (so we just pass PYTHON_VERSION)

Originally posted by @amoeba in #3823 (review)