support free-threaded Python #697

Job	Run time
build sdist	22s
bench	1m 44s
build pgo-optimized on ${{ matrix.os }} / ${{ matrix.interpreter }}	0s
build on ${{ matrix.os }} (${{ matrix.target }} - ${{ matrix.interpreter \|\| 'all' }}${{ (((matrix.os == 'linux') && format(' - {0}', (((matrix.manylinux == 'auto') && 'manylinux') \|\| matrix.manylinux))) \|\| '') }})	0s
fuzz on ubuntu	5m 26s
fuzz skip	5m 27s
lint	39s
fuzz on macos	5m 30s
resolve	11s
test jiter-python 3.13	47s
test jiter-python 3.13t	55s
test build on ${{ matrix.target }}-${{ matrix.distro }}	0s
test build on ${{ matrix.os }}	0s
test rust-stable on ubuntu, Python 3.13	58s
test rust-stable on macos, Python 3.13	59s
test rust-1.75 on ubuntu, Python	38s
test rust-stable on ubuntu, Python 3.13t	38s
test rust-nightly on ubuntu, Python	1m 6s
inspect-pypi-assets	0s
check	2s
release	0s
release-python	0s
	25m 22s

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