update brewu method

Homebrew decided to not change the behaviour of `brew upgrade` so
`brew upgrade --all` is equivalent to `brew upgrade` without any other
arguments (so the `--all` is a no-op and can be removed).

modules/homebrew/init.zsh

@@ -20,7 +20,7 @@ alias brewC='brew cleanup --force'
 alias brewi='brew install'
 alias brewl='brew list'
 alias brews='brew search'
-alias brewu='brew update && brew upgrade --all'
+alias brewu='brew update && brew upgrade'
 alias brewx='brew remove'
 
 # Homebrew Cask