support `float_mode='decimal'` #544

Job	Run time
build pgo-optimized on ${{ matrix.os }} / ${{ matrix.interpreter }}	0s
bench	2m 23s
build on ${{ matrix.os }} (${{ matrix.target }} - ${{ matrix.interpreter \|\| 'all' }}${{ (((matrix.os == 'linux') && format(' - {0}', (((matrix.manylinux == 'auto') && 'manylinux') \|\| matrix.manylinux))) \|\| '') }})	0s
build sdist	9s
fuzz skip	5m 50s
resolve	3s
lint	50s
fuzz on ubuntu-latest	6m 20s
fuzz on macos-latest	6m 13s
test on macos-latest	1m 56s
test jiter-python	57s
test on macos-latest	51s
test build on ${{ matrix.target }}-${{ matrix.distro }}	0s
test build on ${{ matrix.os }}	0s
test rust-stable on linux	1m 52s
test rust-nightly on linux	1m 32s
test rust-1.73.0 on linux	57s
inspect-pypi-assets	0s
check	3s
release	0s
release-python	0s
	29m 56s

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