refactor(.gitignore): update firebase-config to firebase-key, add firebase-messaging-sw

.gitignore

@@ -156,10 +156,10 @@ dump.rdb
 *.DS_Store
 
 # Firebase configuration
-firebase-config.json
+firebase-key.json
 firebase.json
 static/js/firebase-config.js
-@firebase-key.json
+static/firebase-messaging-sw.js
 
 # Environment files
 .env
@@ -175,7 +175,5 @@ local_settings.py
 *_credentials.json
 *_secret.json
 
-@firebase-messaging-sw.js
-@firebase-config.js
 firebase-key.json
 student-management-syste-2e040-firebase-adminsdk-fbsvc-6335c3d2f9.json