Add conditional trigger for backend workflow

Author: McNaBry

.github/workflows/backend.yml

@@ -3,6 +3,7 @@ name: Deploy Backend Services
 on:
   push:
     branches: [ 'main' ]
+    paths: [ 'services/match/**', 'services/question/**', 'services/user/**' ]
 
   # Allows you to run this workflow manually from the Actions tab
   workflow_dispatch: