Revert "[llvm-objdump][macho] Add support for ObjC relative method lists (#84250)"

This reverts llvm/llvm-project#84250, commit aa610064.

See build failures:
https://lab.llvm.org/buildbot/#/builders/178/builds/7028
https://lab.llvm.org/buildbot/#/builders/182/builds/9282
https://lab.llvm.org/buildbot/#/builders/186/builds/15299
https://lab.llvm.org/buildbot/#/builders/187/builds/14564