chore: add dry false config to CleanWebpackPlugin (#14691)

superset-frontend/webpack.config.js

@@ -146,6 +146,7 @@ if (!process.env.CI) {
 if (!isDevServer) {
   plugins.push(
     new CleanWebpackPlugin({
+      dry: false,
       // required because the build directory is outside the frontend directory:
       dangerouslyAllowCleanPatternsOutsideProject: true,
     }),