GitHub Actions: Update to Godot 3.3.3 for HTML5 deployment

.github/workflows/export_html5.yml

@@ -5,14 +5,14 @@ on:
       - master
 
 env:
-  GODOT_VERSION: 3.3
+  GODOT_VERSION: 3.3.3
 
 jobs:
   export-html5:
     name: Export projects to HTML5 and deploy to GitHub Pages
     runs-on: ubuntu-20.04
     container:
-      image: barichello/godot-ci:3.3
+      image: barichello/godot-ci:3.3.3
     steps:
       - name: Checkout
         uses: actions/[email protected]