feat: Add Python 3.14 freethreaded support #851

Job	Run time
lint	10s
test-freethreaded (ubuntu-22.04, 3.14.0, x64, linux)	9s
test-freethreaded (windows-2022, 3.14.0, x64, win32)	21s
test-freethreaded (macos-14, 3.14.0, x64, darwin)	13s
typecheck	10s
test (pypy-3.10, windows-2022)	25s
test (pypy-3.10, ubuntu-22.04)	14s
test (pypy-3.10, macos-14)	35s
test (3.10, windows-2022)	27s
test (pypy-3.11, macos-14)	23s
test (pypy-3.11, ubuntu-22.04)	11s
test (3.11, windows-2022)	28s
test (pypy-3.11, windows-2022)	50s
test (3.10, ubuntu-22.04)	11s
test (3.12, ubuntu-22.04)	13s
test (3.12, windows-2022)	33s
test (3.11, ubuntu-22.04)	12s
test (3.11, macos-14)	11s
test (3.14.0, windows-2022)	1m 22s
test (3.13, ubuntu-22.04)	9s
test (3.12, macos-14)	12s
test (3.10, macos-14)	31s
test (3.14.0, macos-14)	34s
test (3.14.0, ubuntu-22.04)	17s
test (3.13, macos-14)	13s
test (3.13, windows-2022)	23s
	9m 37s

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