Fix workflow triggers and generator imports

Author: shai-almog

.github/workflows/generate-codenameone-skins.yml

@@ -4,6 +4,7 @@ on:
   workflow_dispatch:
   push:
     paths:
+      - '.github/workflows/**'
       - '**/*.yml'
       - '**/*.yaml'
 

scripts/generate_missing_skins.py

@@ -20,7 +20,7 @@
 import hashlib
 import json
 from pathlib import Path
-from typing import Dict, List, Tuple
+from typing import Dict, Iterable, List, Tuple
 from zipfile import ZIP_DEFLATED, ZipFile
 
 REPO_ROOT = Path(__file__).resolve().parents[1]