Bump actions/upload-artifact from 2 to 3 (#421)

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 2 to 3.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](https://github.com/actions/upload-artifact/compare/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/main.yml

@@ -15,7 +15,7 @@ jobs:
     - name: Compile
       run: make
 
-    - uses: actions/upload-artifact@v2
+    - uses: actions/upload-artifact@v3
       with:
         name: examples
         path: examples/*.pdf