fix: actions-runner stopped working

.forgejo/workflows/nightly-update.yaml

@@ -3,20 +3,15 @@ on:
     - cron: 0 */6 * * *
   
 jobs:
-  UpdateFlake:
-    runs-on: native
-
+  updateflake:
     steps:
       - name: Check out repository code
         uses: actions/checkout@v4
-      - name: Update flake
-        run: | 
-          cd ${{ gitea.workspace }}
+      - run: | 
+          cd ${{ env.FORGEJO_WORKSPACE }}
           nix flake update
-      - name: Commit new Flake.lock
-        run: |
+      - run: |
           git config --local user.email "christoph.hollizeck@hey.com"
           git config --local user.name "forgjo-actions[bot]"
           git commit -a -m "chore: update flake"
-      - name: Push changes
-        run: git push
+      - run: git push