Run docs on ubuntu (#314)

Author: blink1073

.github/workflows/main.yml

@@ -28,7 +28,7 @@ jobs:
 
   test_docs:
     name: Test Docs
-    runs-on: windows-latest
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - uses: jupyterlab/maintainer-tools/.github/actions/base-setup@v1