Remove unnecessary git fetch origin (#292)

.github/workflows/_upgrade-test.yaml

@@ -13,9 +13,8 @@ jobs:
       - name: install latest warden operator from the release
         run: |
           helm install --set global.config.data.logging.level=debug --set admission.enabled=true warden https://github.com/kyma-project/warden/releases/latest/download/warden-chart.tgz
-      - name: checkout to latest commit and install warden
+      - name: install warden from the branch
         run: |
-          git checkout $(git rev-parse origin/main)
           make install
       - name: run integration tests
         run: make run-integration-tests