Fix CI bug when multirepo branches don't exist

Author: robtaylor

.github/workflows/test-examples.yml

@@ -41,8 +41,7 @@ jobs:
         if: github.event_name == 'pull_request'
         run: |
           git remote update
-          git checkout ${{ github.head_ref }}
-          if [ $? -eq 0 ]; then
+          if git checkout ${{ github.head_ref }}; then
              echo "Using branch ${{github.head_ref}}"
              echo "found-branch=1\n" >> $GITHUB_OUTPUT
           else
@@ -56,8 +55,7 @@ jobs:
         if: github.event_name == 'pull_request' && steps.check-head-ref == 0
         run: |
           git remote update
-          git checkout ${{ github.base_ref }}
-          if [ $? -eq 0 ]; then
+          if git checkout ${{ github.base_ref }}; then
              echo "Using branch ${{github.base_ref}}"
              echo "found-branch=1\n" >> $GITHUB_OUTPUT
           else