use upload-artifact@v4

Author: jviau

.github/workflows/validate-build.yml

@@ -48,7 +48,7 @@ jobs:
       run: dotnet pack $solution --configuration $config --no-build
 
     - name: Upload
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: pkg
         path: out/pkg