fix: Fix new PRs not being created when release from CI

[naoyukik]

Perhaps this is missing.

      # Set environment variables
      - name: Export Properties
        id: properties
        shell: bash
        run: |
          CHANGELOG="$(cat << 'EOM' | sed -e 's/^[[:space:]]*$//g' -e '/./,$!d'
          ${{ github.event.release.body }}
          EOM
          )"

          echo "changelog<<EOF" >> $GITHUB_OUTPUT
          echo "$CHANGELOG" >> $GITHUB_OUTPUT
          echo "EOF" >> $GITHUB_OUTPUT