rubocops/uses_from_macos: remove openlibm
rubocops/uses_from_macos: remove openlibm

This is not provided by macOS. See

    https://github.com/Homebrew/homebrew-core/pull/76528

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