fix: Update actions/upload-artifact to version v4

- see https://github.blog/changelog/2024-02-13-deprecation-notice-v1-and-v2-of-the-artifact-actions/

.github/workflows/build-examples.yml

@@ -56,7 +56,7 @@ jobs:
     - name: Build examples
       run: cd examples && bash build-examples.sh && cd ..
     - name: Add generated example files
-      uses: actions/upload-artifact@v2
+      uses: actions/upload-artifact@v4
       with:
         name: build-files
         path: |