Reduce vortex-fastlanes debug symbols by halving `unchecked_unpack_cmp` monomorphization #5043

Job	Run time
Python (wheel build)	5m 21s
check-java-publish-build (aarch64-unknown-linux-gnu, runs-on=29299530130/runner=arm64-medium/imag...	1m 50s
check-java-publish-build (x86_64-unknown-linux-gnu, runs-on=29299530130/runner=amd64-medium/image...	1m 19s
Rust publish dry-run	25s
Compat check / compat-test	2m 52s
	11m 47s

Provide feedback