[compiler-rt] [compiler-rt][memprof] Do not add libdl to MEMPROF_UNITTEST_LINK_LIBRARIES (PR #98221)

[Alexander Richardson via llvm-commits]

https://github.com/arichardson approved this pull request.

As far as I recall libdl is only needed for dl_iterate_phdrs which is used by some sanitizers (and won't be pulled in implicitly for static linking), but if memprof does not need it we can defintely drop it.

https://github.com/llvm/llvm-project/pull/98221