workflows/release-tasks: Upload release notes as an artifact

This make sure the docs are always available and can be manually uploaded
if a later step fails.

Reviewed By: thieta

Differential Revision: https://reviews.llvm.org/D145996

.github/workflows/release-tasks.yml

@@ -48,6 +48,12 @@ jobs:
           ./llvm/utils/release/build-docs.sh -srcdir llvm
           ./llvm/utils/release/github-upload-release.py --token ${{ github.token }} --release ${{ steps.validate-tag.outputs.release-version }} upload --files *doxygen*.tar.xz
 
+      - name: Create Release Notes Artifact
+        uses: actions/download-artifact@v1
+        with:
+          name: release-notes
+          path: docs-build/html-export/
+
       - name: Clone www-releases
         if: ${{ !contains(steps.validate-tag.outputs.release-version, 'rc') }}
         uses: actions/checkout@v3