ci: update readme-stars workflow (#36)

* update checkout action to v4
* update git-auto-commit-action to v5, add required write permission
* use variable for run condition, check on job level

.github/workflows/readme-stars.yml

@@ -9,22 +9,16 @@ on:
 jobs:
     update-readme:
         runs-on: ubuntu-latest
+        if: ${{ vars.AOC_ENABLED == 'true' }}
+        permissions:
+            contents: write
         steps:
-            - uses: actions/checkout@v3
-              if: ${{ env.AOC_ENABLED }}
-              env:
-                  AOC_ENABLED: ${{ secrets.AOC_ENABLED }}
+            - uses: actions/checkout@v4
             - uses: k2bd/advent-readme-stars@v1
-              if: ${{ env.AOC_ENABLED }}
-              env:
-                  AOC_ENABLED: ${{ secrets.AOC_ENABLED }}
               with:
                   userId: ${{ secrets.AOC_USER_ID }}
                   sessionCookie: ${{ secrets.AOC_SESSION }}
                   year: ${{ secrets.AOC_YEAR }}
-            - uses: stefanzweifel/git-auto-commit-action@v4
-              if: ${{ env.AOC_ENABLED }}
-              env:
-                  AOC_ENABLED: ${{ secrets.AOC_ENABLED }}
+            - uses: stefanzweifel/git-auto-commit-action@v5
               with:
                   commit_message: "update readme progess"