fix(treefmt): add src/options/flags.rs to rustfmt.excludes

Signed-off-by: Sandro-Alessio Gierens <sandro@gierens.de>

treefmt.nix

@@ -10,5 +10,6 @@
   };
   settings = {
     formatter.shellcheck.includes = ["*.sh" "./completions/bash/eza"];
+    formatter.rustfmt.excludes = ["src/options/flags.rs"];
   };
 }