Update build.yml to use /upload-artifact@v4

/upload-artifact@v1 is deprecated: https://github.blog/news-insights/product-news/get-started-with-v4-of-github-actions-artifacts/

Author: hwayne

.github/workflows/build.yml

@@ -34,7 +34,7 @@ jobs:
           pip install -r requirements.txt
           sphinx-build -D todo_include_todos=0 docs ./docs/_build/html/
       # not necessary for deployment, but makes output observable
-      - uses: actions/upload-artifact@v1
+      - uses: actions/upload-artifact@v4
         with:
           name: DocumentationHTML
           path: docs/_build/html/