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

Job	Run time
Rust tests (asan)	4m 36s
Rust/C++ FFI tests (asan)	1m 38s
Rust tests (miri)	1m 30s
Rust tests (tsan)	4m 29s
Rust/C++ FFI tests (tsan)	1m 30s
Mirror DuckDB to R2 / Resolve DuckDB version and check R2	5s
DuckDB libraries available in R2	2s
Mirror DuckDB to R2 / Mirror DuckDB ${{ matrix.archive }} to R2	-1s
Rust tests (coverage) (tests)	6m 14s
	20m 3s

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