add `OnceLockExt` extension trait to help initialize `OnceLock` #11076

Job	Run time
fmt	15s
resolve	3s
careful	0s
check-feature-powerset ${{ matrix.rust }}	0s
python${{ matrix.python-version }}-${{ matrix.platform.python-architecture }} ${{ matrix.platform.os }} rust-${{ matrix.rust }}	0s
check-msrv	6m 50s
coverage windows-latest	16m 20s
docsrs	0s
coverage macos-14	7m 33s
emscripten	0s
coverage ubuntu-latest	10m 58s
semver-checks	2m 38s
clippy/aarch64-apple-darwin/stable	7m 56s
clippy/x86_64-unknown-linux-gnu/stable	8m 11s
test-cross-compilation ${{ matrix.os }} -> ${{ matrix.target }}	0s
clippy/powerpc64le-unknown-linux-gnu/stable	8m 10s
test-cross-compilation-windows	0s
test-debug	0s
clippy/s390x-unknown-linux-gnu/stable	8m 12s
clippy/wasm32-wasi/stable	8m 12s
test-free-threaded	0s
clippy/x86_64-pc-windows-msvc/stable	7m 58s
test-version-limits	0s
clippy/i686-pc-windows-msvc/stable	7m 56s
valgrind	0s
clippy/x86_64-unknown-linux-gnu/beta	8m 11s
python3.12-x64 ubuntu-latest rust-nightly / build	34s
python3.12-x64 macos-13 rust-stable / build	17m 51s
python3.12-arm64 macos-14 rust-stable / build	6m 37s
python3.12-x64 ubuntu-latest rust-stable / build	9m 42s
python3.12-x64 windows-latest rust-stable / build	16m 4s
python3.12-x86 windows-latest rust-stable / build	11m 32s
conclusion	1s
	2h 51m 44s

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