formula: ensure `rpath` is passed a valid `target`
formula: ensure `rpath` is passed a valid `target`

Setting `target` to a path outside `HOMEBREW_PREFIX` is not portable,
and will be invalid for some Homebrew installations.

If we want to add an `rpath` outside of `HOMEBREW_PREFIX`, we should
just use the absolute path instead.

See discussion at Homebrew/homebrew-core#110520.

Homebrew/brew,Homebrew/brew,Homebrew/brew,MikeMcQuaid/brew,nandub/brew,nandub/brew,MikeMcQuaid/brew,MikeMcQuaid/brew,Homebrew/brew,nandub/brew,MikeMcQuaid/brew,nandub/brew