ci: avoid helm repo update for performance reasons

Author: consideRatio

.github/workflows/test.yml

@@ -78,15 +78,11 @@ jobs:
       - name: Install JupyterHub chart for main tests
         if: matrix.test == 'main'
         run: |
-            helm repo add jupyterhub https://jupyterhub.github.io/helm-chart/
-            helm repo update
             ./testing/local-binder-k8s-hub/install-jupyterhub-chart
 
       - name: Install JupyterHub chart for auth tests
         if: matrix.test == 'auth'
         run: |
-            helm repo add jupyterhub https://jupyterhub.github.io/helm-chart/
-            helm repo update
             ./testing/local-binder-k8s-hub/install-jupyterhub-chart --auth
 
       - name: Use chartpress to create the helm chart

testing/local-binder-k8s-hub/install-jupyterhub-chart

@@ -38,7 +38,8 @@ with NamedTemporaryFile(mode="w") as tmp:
 
     cmd = ['helm', 'upgrade', '--install', 'binderhub-test']
     cmd.extend([
-        'jupyterhub/jupyterhub',
+        'jupyterhub',
+        '--repo=https://jupyterhub.github.io/helm-chart/',
         f'--version={_get_jupyterhub_dependency_version()}',
         f'--values={tmp.name}',
         f'--values={os.path.join(here, "jupyterhub-chart-config.yaml")}',