[CI] Use updated latex workflow

.gitea/workflows/build-docs.yml

@@ -17,7 +17,7 @@ jobs:
           password: ${{ secrets.REGISTRY_USER_PASSWORD }}
           registry: ${{ vars.REGISTRY_BASE_URL }}
       - name: Run build
-        uses: actions/latex@v1
+        uses: actions/latex@v2
         with:
           args: "-latexoption=-file-line-error -latexoption=-interaction=nonstopmode docs/docs.tex"
       - name: Upload compiled docs