Add py free-threaded support #1704

Job	Run time
Build and test with .NET	18s
Build and test cmake:gcc-old	37s
Build and test cmake:gcc	42s
Build and test cmake:clang-old	48s
Build and test cmake:clang	48s
Build and test cmake:package	1m 2s
Build and test cmake:clang:tsan	1m 6s
Build and test cmake:clang:ubsan	1m 9s
Build and test cmake-osx:clang	30s
Build and test cmake:clang:asan	56s
Build and test cmake:static	45s
Build and test cmake:qemu-arm-neon-gcc	2m 31s
Build and test cmake-osx:gcc	31s
Build and test cmake-win64:msvc-dbg	36s
Build and test cmake-ios:clang	29s
Build and test fuzz:clang	47s
Build and test python3.14:clang	49s
Build and test maven	58s
Build and test bazel:root	1m 2s
Build and test cmake-win64:msvc-rel	57s
Build and test python3.14-win	39s
Build and test python3.14t:clang	58s
Build and test bazel:java	2m 25s
Build and test bazel:go	1m 23s
Build and test bazel-osx:root	1m 18s
Build and test bazel:research	53s
Build and test bazel-osx:research	59s
Build and test bazel-win:root	1m 29s
Build and test bazel-win:research	1m 3s
Build and test bazel-osx:java	2m 9s
Build and test bazel-osx:go	1m 23s
	32m 0s

Provide feedback