extend/os/mac/keg_relocate: fix post-bottling dylib ID relocation
extend/os/mac/keg_relocate: fix post-bottling dylib ID relocation

Running `brew bottle` changes dylib IDs, install names, and rpaths into
placeholders for the bottle, creates a bottle tarball, and then changes
the placeholders back to their correct values.

With my refactoring in #11358, the behaviour of this relocation changed:
dylib IDs would no longer be changed back from placeholders into their
correct values after the creation of the bottle tarball.

Homebrew/brew,Homebrew/brew,Homebrew/brew,nandub/brew,MikeMcQuaid/brew,EricFromCanada/brew,JCount/brew,Homebrew/brew,JCount/brew,EricFromCanada/brew,MikeMcQuaid/brew,EricFromCanada/brew,nandub/brew,claui/brew,claui/brew,EricFromCanada/brew,nandub/brew,claui/brew,claui/brew,JCount/brew,MikeMcQuaid/brew,MikeMcQuaid/brew,JCount/brew,nandub/brew