[CI] Fix syntax

.gitea/workflows/build-docs.yml

@@ -14,7 +14,7 @@ jobs:
         uses: https://github.com/docker/login-action
         with:
           username: ${{ vars.REGISTRY_USER_USERNAME }}
-          username: ${{ secrets.REGISTRY_USER_PASSWORD }}
+          password: ${{ secrets.REGISTRY_USER_PASSWORD }}
           registry: ${{ vars.REGISTRY_BASE_URL }}
       - name: Run build
         uses: actions/latex@v1