nixos/zsh: use `escapeShelLArg' for shell aliases (#47471)

Previously single quotes were used by default for aliases and the module
never warned about possible collisions when having a shell alias which
relies on single quotes.

Adding `escapeShellArg` works around this fixes the issue and ensures that a
properly quoted value is written to `/etc/zshrc`.

nixos/modules/programs/zsh/zsh.nix

@@ -11,7 +11,7 @@ let
   cfg = config.programs.zsh;
 
   zshAliases = concatStringsSep "\n" (
-    mapAttrsFlatten (k: v: "alias ${k}='${v}'") cfg.shellAliases
+    mapAttrsFlatten (k: v: "alias ${k}=${escapeShellArg v}") cfg.shellAliases
   );
 
 in