fix: should not enable cssnano in dev (#8008)

Author: 9aoy

.changeset/fuzzy-shoes-invent.md

@@ -0,0 +1,7 @@
+---
+'@modern-js/uni-builder': patch
+---
+
+fix: should not enable cssnano when injectStyles is enabled in dev environment
+
+fix: 开启 injectStyles 时 dev 环境下不启用 cssnano

packages/cli/uni-builder/src/shared/plugins/postcss.ts

@@ -70,7 +70,7 @@ export const pluginPostcss = (
       const cssSupport = getCssSupport(config.output.overrideBrowserslist!);
       const enableExtractCSS = !config.output?.injectStyles;
 
-      const enableCssMinify = !enableExtractCSS && isProd;
+      const enableCssMinify = !enableExtractCSS && isProd();
 
       const cssnanoOptions: Options = {
         preset: [