Bump actions/upload-artifact from 2.3.0 to 2.3.1 (#89)

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 2.3.0 to 2.3.1.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v2.3.0...v2.3.1)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

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

.github/workflows/tests.yaml

@@ -49,7 +49,7 @@ jobs:
       - name: 🚀 Run pytest
         run: poetry run pytest --cov omnikinverter tests
       - name: ⬆️ Upload coverage artifact
-        uses: actions/[email protected].0
+        uses: actions/[email protected].1
         with:
           name: coverage-${{ matrix.python }}-${{ matrix.os }}
           path: .coverage