ci: add missing GH_TOKEN env for gh pr create command (#40)

Author: shuuji3

.github/workflows/update-lexicons.yml

@@ -38,6 +38,7 @@ jobs:
         if: ${{ steps.check-version-change.outputs.VERSION_CHANGED == 'yes' }}
         env:
           BRANCH_NAME: gh-actions-update-lexicons
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
           git config user.name "github-actions[bot]"
           git config user.email "41898282+github-actions[bot]@users.noreply.github.com"