Bump actions/upload-artifact from 3 to 4

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 3 to 4.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v3...v4)

---
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>

.github/workflows/cygwin.yml

@@ -162,7 +162,7 @@ jobs:
 
     # upload test logs to facilitate investigation of problems
     - name: Upload test logs
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: testlogs
         path: |