Add docker/login-action to hypha ci action.

Author: frjo

.github/workflows/hypha-ci.yml

@@ -26,6 +26,15 @@ jobs:
       - name: Run pre-commit
         uses: pre-commit/action@v3.0.1
 
+  login:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Login to Docker Hub
+        uses: docker/login-action@v4
+        with:
+          username: ${{ vars.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
   django-checks:
     runs-on: ubuntu-latest
     timeout-minutes: 5