Keep removing pre-Python 3.9 code #518

Job	Run time
clang_TSAN	4m 25s
make_ios_matrix	4s
make_macos_matrix	3s
make_linux_matrix	4s
make_windows_matrix	7s
python_sdist	12s
make_run_parallel_matrix	6s
pytest-run-parallel (ubuntu-24.04, 3.14t)	43s
pytest-run-parallel (macos-15, 3.14t)	1m 42s
pytest-run-parallel (windows-2025, 3.14t)	2m 3s
ios (cp313-ios_arm64_iphoneos, iphoneos)	27s
macos (cp314-macosx_arm64, 11.0, arch -arm64 bash --noprofile --norc -eo pipefail {0})	4m 5s
windows (cp314t-win_amd64)	1m 21s
ios (cp313-ios_arm64_iphonesimulator, iphonesimulator)	3m 59s
macos (cp314t-macosx_x86_64, macos-15-intel)	17m 43s
macos (cp314t-macosx_arm64, 11.0, arch -arm64 bash --noprofile --norc -eo pipefail {0})	5m 26s
ios (cp314-ios_arm64_iphoneos, iphoneos)	25s
ios (cp314-ios_arm64_iphonesimulator, iphonesimulator)	2m 59s
windows (cp314t-win32)	1m 29s
macos (cp314-macosx_x86_64, macos-15-intel)	9m 3s
windows (cp314-win32)	1m 47s
windows (cp314t-win_arm64, windows-11-arm)	1m 35s
linux (cp39-manylinux_aarch64, aarch64)	4m 16s
linux (cp314t-manylinux_aarch64, aarch64)	4m 15s
linux (cp314-musllinux_x86_64, x86_64)	5m 58s
windows (cp314-win_arm64, windows-11-arm)	1m 38s
linux (cp314t-musllinux_x86_64, x86_64)	5m 57s
linux (cp311-musllinux_i686, i686)	5m 8s
linux (cp314t-manylinux_x86_64, x86_64)	4m 27s
linux (cp314-manylinux_aarch64, aarch64)	4m 3s
linux (cp313-manylinux_i686, i686)	4m 50s
linux (cp314t-musllinux_aarch64, aarch64)	5m 4s
windows (cp314-win_amd64)	1m 56s
linux (cp314-musllinux_aarch64, aarch64)	4m 35s
linux (cp314-manylinux_x86_64, x86_64)	4m 19s
check	5s
merge_artifacts	0s
	1h 56m 19s

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