chore: temporary fix for hermetic library generation workflow (#3310)

Author: diegomarquezp

.github/workflows/hermetic_library_generation.yaml

@@ -19,12 +19,10 @@ on:
 
 env:
   HEAD_REF: ${{ github.head_ref }}
-  REPO_FULL_NAME: ${{ github.event.pull_request.head.repo.full_name }}
-
 jobs:
   library_generation:
     # skip pull requests coming from a forked repository
-    if: github.env.REPO_FULL_NAME == github.repository
+    if: github.event.pull_request.head.repo.full_name == github.repository
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4