Make environment dropdown readonly so Production is still visible

Author: lucwollants

app/Nova/Actions/UdbOrganizer/RequestUdbOrganizer.php

@@ -93,7 +93,8 @@ public function fields(NovaRequest $request): array
                     Environment::Production->value => 'Production',
                 ])
                 ->default(Environment::Production->value)
-                ->rules('required'),
+                ->rules('required')
+                ->readonly(),
         ];
     }