check in refs/heads/ for the branch, use mpes feature branch

.github/workflows/plugin_test.yaml

@@ -31,6 +31,7 @@ jobs:
             tests_to_run: tests/.
           - plugin: pynxtools-mpes
             branches:
+              - update-to-new-nxmpes
               - main
             tests_to_run: tests/.
           - plugin: pynxtools-stm
@@ -71,13 +72,13 @@ jobs:
         id: check-branch
         run: |
           branch_exists=false
-          for branch in ${{ matrix.branches }}; do
-            if git ls-remote --heads https://github.com/FAIRmat-NFDI/${{ matrix.plugin }}.git $branch | grep $branch; then
-              echo "Branch $branch exists."
-              echo "::set-output name=branch::$branch"
-              branch_exists=true
-              break
-            fi
+          for branch in "${{ matrix.branches }}"; do
+          if git ls-remote --heads https://github.com/FAIRmat-NFDI/${{ matrix.plugin }}.git "$branch" | grep -q "refs/heads/$branch"; then
+            echo "Branch $branch exists."
+            echo "branch=$branch" >> $GITHUB_ENV
+            branch_exists=true
+            break
+          fi
           done
           if [ "$branch_exists" = "false" ]; then
             echo "No branches exist."