Bump actions/upload-artifact from v1 to 2.1.0 (#1829)

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from v1 to 2.1.0.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](https://github.com/actions/upload-artifact/compare/v1...ebad382c0953e8c6b4039e8d30dfd19ee7b2a862)

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

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

.github/workflows/ci.yaml

@@ -392,7 +392,7 @@ jobs:
             -o console_output_style=count \
             tests
       - name: Upload coverage artifact
-        uses: actions/upload-artifact@v1
+        uses: actions/upload-artifact@2.1.0
         with:
           name: coverage-${{ matrix.python-version }}
           path: .coverage