robbyrussell: restore prompt spacing (#8148)

themes/robbyrussell.zsh-theme

@@ -1,4 +1,4 @@
-PROMPT="%(?:%{$fg_bold[green]%}➜:%{$fg_bold[red]%}➜)"
+PROMPT="%(?:%{$fg_bold[green]%}➜ :%{$fg_bold[red]%}➜ )"
 PROMPT+=' %{$fg[cyan]%}%c%{$reset_color%} $(git_prompt_info)'
 
 ZSH_THEME_GIT_PROMPT_PREFIX="%{$fg_bold[blue]%}git:(%{$fg[red]%}"