tweak token usage

Author: GroovinChip

.github/workflows/gh_pages.yml

@@ -9,6 +9,8 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
+      - env:
+          GITHUB_TOKEN: ${{ github.token }}
       - uses: actions/checkout@v2
       - uses: subosito/flutter-action@v1
         with:
@@ -25,7 +27,7 @@ jobs:
           git init
           git config user.name "GroovinChip"
           git config user.email "groovinchip@github.com"
-          git remote add secure-origin https://${{ secrets.GITHUB_TOKEN }}@github.com/GroovinChip/macos_ui.git
+          git remote add secure-origin https://username:${GITHUB_TOKEN}@github.com/${GITHUB_REPOSITORY}.git
           git checkout -b gh-pages
           git add .
           git commit -m "update"