fix: skip prepareOutDirPlugin in workers (vitejs#20556)

Author: sapphi-red

packages/vite/src/node/build.ts

@@ -467,7 +467,7 @@ export async function resolveBuildPlugins(config: ResolvedConfig): Promise<{
   return {
     pre: [
       completeSystemWrapPlugin(),
-      prepareOutDirPlugin(),
+      ...(!config.isWorker ? [prepareOutDirPlugin()] : []),
       perEnvironmentPlugin('commonjs', (environment) => {
         const { commonjsOptions } = environment.config.build
         const usePluginCommonjs =