Unify hook settings and fix warning

trace: warning: The option `settings.statix' defined in `/nix/store/plj05iykqma26y930qjf75zxp2qx02sl-source/flake.nix, via option perSystem' has been renamed to `hooks.statix.settings'.

flake-module.nix

@@ -26,14 +26,15 @@
     in {
       check.enable = true;
       settings = {
-        # for some reason statix takes it config differently than all the other hooks.
+        hooks = {
-        settings.statix = {
+          nil.enable = true;
+          statix = {
+            enable = true;
+            settings = {
               format = "stderr";
               ignore = generatedFiles;
             };
-        hooks = {
+          };
-          nil.enable = true;
-          statix.enable = true;
           deadnix = {
             enable = true;
             excludes = generatedFiles;