[CI] Remove login

.gitea/workflows/build-docs.yml

@@ -10,8 +10,6 @@ jobs:
     steps:
       - name: Set up Git repository
         uses: actions/checkout@v6
-      - name: Sign into gitea registry
-        run: docker login ${{ vars.REGISTRY_URL }} -u ${{ vars.REGISTRY_USER_USERNAME }} -p "${{ secrets.REGISTRY_USER_PASSWORD_ESCAPED }}"
       - name: Run build
         uses: actions/latex@main
         with: