Remove ACTIONS_RUNTIME_TOKEN workaround (#396)

The bug has been fixed for a long time in the GitHub version.
The fix commit is d8823bfaed and released in the 4.0.0 and after. The issue also mentions that https://gitea.com/gitea/act_runner/issues/119#issuecomment-738294

Reviewed-on: https://gitea.com/gitea/act_runner/pulls/396
Reviewed-by: techknowlogick <techknowlogick@noreply.gitea.com>
Co-authored-by: lng2020 <nanguanlin6@gmail.com>
Co-committed-by: lng2020 <nanguanlin6@gmail.com>

.gitea/workflows/release-nightly.yml

@@ -78,8 +78,6 @@ jobs:
 
       - name: Build and push
         uses: docker/build-push-action@v4
-        env:
-          ACTIONS_RUNTIME_TOKEN: '' # See https://gitea.com/gitea/act_runner/issues/119
         with:
           context: .
           file: ./Dockerfile

.gitea/workflows/release-tag.yml

@@ -89,8 +89,6 @@ jobs:
 
       - name: Build and push
         uses: docker/build-push-action@v4
-        env:
-          ACTIONS_RUNTIME_TOKEN: '' # See https://gitea.com/gitea/act_runner/issues/119
         with:
           context: .
           file: ./Dockerfile