Bump actions/download-artifact from v2.0.6 to v2.0.8 (#34)

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from v2.0.6 to v2.0.8.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v2.0.6...4a7a711)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/tests.yml

@@ -124,7 +124,7 @@ jobs:
           nox --version
 
       - name: Download coverage data
-        uses: actions/download-artifact@v2.0.6
+        uses: actions/download-artifact@v2.0.8
         with:
           name: coverage-data