Revert "Lazy-load postcss (vercel#31762)"

This reverts commit 92b397f.

.gitignore

@@ -13,7 +13,6 @@ test/node_modules
 # logs & pids
 *.log
 pids
-*.cpuprofile
 
 # coverage
 .nyc_output
@@ -42,4 +41,4 @@ test-timings.json
 .now
 
 # Cache
-*.tsbuildinfo
+*.tsbuildinfo

packages/next/build/webpack-config.ts

@@ -33,6 +33,7 @@ import { NextConfigComplete } from '../server/config-shared'
 import { finalizeEntrypoint } from './entries'
 import * as Log from './output/log'
 import { build as buildConfiguration } from './webpack/config'
+import { __overrideCssConfiguration } from './webpack/config/blocks/css/overrideCssConfiguration'
 import MiddlewarePlugin from './webpack/plugins/middleware-plugin'
 import BuildManifestPlugin from './webpack/plugins/build-manifest-plugin'
 import { JsConfigPathsPlugin } from './webpack/plugins/jsconfig-paths-plugin'
@@ -1890,6 +1891,8 @@ export default async function getBaseWebpackConfig(
           (e) => (e as any).__next_css_remove !== true
         )
     }
+  } else if (!config.future.strictPostcssConfiguration) {
+    await __overrideCssConfiguration(dir, supportedBrowsers, webpackConfig)
   }
 
   // Inject missing React Refresh loaders so that development mode is fast: