update branch getter

Author: m-murasovs

.github/workflows/test-code-samples.yaml

@@ -17,7 +17,7 @@ jobs:
         env:
         #   APIFY_TOKEN: ${{ secrets.CODE_SAMPLE_TESTER_ACTOR_TOKEN }}
           APIFY_TOKEN: apify_api_cUpIjxWrtMdy6Ctqnz9PhYyTjdqWcI4tjFTr
-          BRANCH_NAME: ${{ github.ref_name }}
+          BRANCH_NAME: ${{ github.head_ref || github.ref_name }}
         run: |
           curl --fail-with-body -X POST "https://api.apify.com/v2/acts/X8D0L4wfpO8fCL1uL/run-sync" \
           -H "Content-Type: application/json" \