fix global GHA permissions

Author: chicks-net

.github/workflows/godot-checks.yml

@@ -12,6 +12,9 @@ concurrency:
   group: ci-${{github.actor}}-${{github.head_ref || github.run_number}}-${{github.ref}}-static
   cancel-in-progress: true
 
+# global permissions
+permissions: {}
+
 jobs:
   static-checks:
     runs-on: ubuntu-latest