fix: normalize public filter

packages/vite-plugin-uni/src/utils/filter.ts

 import path from 'path'
-
+import slash from 'slash'
 import { createFilter } from '@rollup/pluginutils'
 import { PUBLIC_DIR } from '@dcloudio/uni-cli-shared'
 
 export function createPublicFileFilter(base: string = '/') {
-  const publicDir = path.join(base, PUBLIC_DIR + '/**/*')
-  const uniModulesDir = path.join(base, 'uni_modules/*/' + PUBLIC_DIR + '/**/*')
+  const publicDir = slash(path.join(base, PUBLIC_DIR + '/**/*'))
+  const uniModulesDir = slash(
+    path.join(base, 'uni_modules/*/' + PUBLIC_DIR + '/**/*')
+  )
   return createFilter([publicDir, uniModulesDir])
 }