Update to actions/upload-artifact@v4

Author: kelunik

.github/workflows/ci.yml

@@ -74,7 +74,7 @@ jobs:
         run: php -dphar.readonly=0 vendor/bin/phar-builder package
 
       - name: Upload phar
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: acme-client.phar
           path: |