Bump actions/upload-artifact from 2 to 3 (#253)

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 2 to 3.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v2...v3)

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

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

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

.github/workflows/joss.yml

@@ -32,7 +32,7 @@ jobs:
           JOURNAL: joss
 
       - name: Upload the generated files as an artifact
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v3
         with:
           path: joss
           name: joss

.github/workflows/tests.yml

@@ -105,7 +105,7 @@ jobs:
           python -m pip install -U pip
           python -m pip install -U build
           python -m build .
-      - uses: actions/upload-artifact@v2
+      - uses: actions/upload-artifact@v3
         with:
           path: dist/*