oh-my-zsh: fix 'preLoaded' option documentation (#352266)

Author: Aleksanaa

nixos/modules/programs/zsh/oh-my-zsh.nix

@@ -93,7 +93,7 @@ in
           default = "";
           description = ''
             Shell commands executed before the `oh-my-zsh` is loaded.
-            For example, to disable async git prompt write `zstyle ':omz:alpha:lib:git' async-prompt force` (more information https://github.com/ohmyzsh/ohmyzsh?tab=readme-ov-file#async-git-prompt)
+            For example, to disable async git prompt write `zstyle ':omz:alpha:lib:git' async-prompt no` (more information https://github.com/ohmyzsh/ohmyzsh?tab=readme-ov-file#async-git-prompt)
           '';
         };
       };