docs(git): Unlist long-removed aliases

There are some aliases, whose functionality has long been reassigned to
different aliases, but have not been reused for new commands, yet are
still documented in the README. Remove them.

lib/git.zsh

@@ -117,7 +117,7 @@ function _omz_git_prompt_status() {
   fi
 
   # For each status prefix, do a regex comparison
-  for status_prefix in ${(k)prefix_constant_map}; do
+  for status_prefix in "${(@k)prefix_constant_map}"; do
     local status_constant="${prefix_constant_map[$status_prefix]}"
     local status_regex=$'(^|\n)'"$status_prefix"