Conditional labelling (#1666)

Co-authored-by: wixoa <[email protected]>

.github/workflows/pr-labeler.yml

@@ -17,6 +17,7 @@ jobs:
           repoToken: "${{ secrets.GITHUB_TOKEN }}"
           commentOnDirty: "This pull request has conflicts, please resolve those before we can evaluate the pull request."
       - name: Apply Size Label
+        if: ${{ github.ref != 'refs/heads/master' }}
         uses: pascalgn/[email protected]
         env:
           GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"