Fix strict behavior for unions #5709

Job	Run time
build on ${{ matrix.os }} (${{ matrix.target }} - ${{ matrix.interpreter \|\| 'all' }}${{ (((matrix.os == 'linux') && format(' - {0}', (((matrix.manylinux == 'auto') && 'manylinux') \|\| matrix.manylinux))) \|\| '') }})	0s
build pgo-optimized on ${{ matrix.os }} / ${{ matrix.interpreter }}	0s
rust benchmarks	2m 8s
build sdist	22s
build-wasm-emscripten	1m 33s
coverage	1m 14s
lint	1m 15s
test-debug 3.13	54s
test MSRV	2m 42s
test-debug pypy3.10	3m 14s
test on ubuntu	1m 51s
test-pydantic-integration	1m 1s
test on macos	2m 20s
test 3.9	1m 54s
test on windows	4m 9s
test 3.10	2m 4s
test 3.11	1m 48s
test 3.12	1m 47s
test 3.13	1m 43s
test 3.13t	2m 3s
test pypy3.9	4m 9s
test pypy3.10	4m 13s
test build on ${{ matrix.target }}-${{ matrix.distro }}	0s
test build on ${{ matrix.os }}	0s
inspect-pypi-assets	0s
check	2s
release	0s
	42m 26s

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