Update main.yml

Author: kwagyeman

.github/workflows/main.yml

@@ -19,7 +19,7 @@ jobs:
         pre-build-command: "rm micropython/docs/requirements.txt && pip install sphinx -U && pip install sphinx_rtd_theme -U && pip install sphinx"
         docs-folder: "micropython/docs/"
 
-    - uses: actions/upload-artifact@v1
+    - uses: actions/upload-artifact@v4
       with:
         name: html
         path: micropython/docs/build/html/