Update postcss-loader to 4.3.0 (vercel#25197)

## Feature

- [ ] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.

This pull request upgrades `postcss-loader` from `4.0.3` to `4.3.0`. Version `4.3.0` [adds support](webpack-contrib/postcss-loader#525) for the `dir-dependency` message type which PostCSS plugins can use to register directories as dependencies ([documentation](https://github.com/postcss/postcss/blob/main/docs/guidelines/plugin.md#31-use-messages-to-specify-dependencies)).

packages/next/package.json

@@ -226,7 +226,7 @@
     "ora": "4.0.4",
     "path-to-regexp": "6.1.0",
     "postcss-flexbugs-fixes": "5.0.2",
-    "postcss-loader": "4.0.3",
+    "postcss-loader": "4.3.0",
     "postcss-preset-env": "6.7.0",
     "postcss-scss": "3.0.5",
     "recast": "0.18.5",

packages/next/taskfile.js

@@ -436,7 +436,13 @@ externals['postcss-loader'] = 'next/dist/compiled/postcss-loader'
 export async function ncc_postcss_loader(task, opts) {
   await task
     .source(opts.src || relative(__dirname, require.resolve('postcss-loader')))
-    .ncc({ packageName: 'postcss-loader', externals })
+    .ncc({
+      packageName: 'postcss-loader',
+      externals: {
+        ...externals,
+        'schema-utils': 'next/dist/compiled/schema-utils3',
+      },
+    })
     .target('compiled/postcss-loader')
 }
 // eslint-disable-next-line camelcase

yarn.lock

@@ -12827,16 +12827,16 @@ postcss-loader@3.0.0:
     postcss-load-config "^2.0.0"
     schema-utils "^1.0.0"
 
-postcss-loader@4.0.3:
-  version "4.0.3"
-  resolved "https://registry.yarnpkg.com/postcss-loader/-/postcss-loader-4.0.3.tgz#337f51bbdfb02269fb42f7db9fc7f0a93c1b2e3f"
-  integrity sha512-jHboC/AOnJLPu8/974hODCJ/rNAa2YhhJOclUeuRlAmFpKmEcBY6az8y1ejHyYc2LThzPl8qPRekh2Yz3CiRKA==
+postcss-loader@4.3.0:
+  version "4.3.0"
+  resolved "https://registry.yarnpkg.com/postcss-loader/-/postcss-loader-4.3.0.tgz#2c4de9657cd4f07af5ab42bd60a673004da1b8cc"
+  integrity sha512-M/dSoIiNDOo8Rk0mUqoj4kpGq91gcxCfb9PoyZVdZ76/AuhxylHDYZblNE8o+EQ9AMSASeMFEKxZf5aU6wlx1Q==
   dependencies:
     cosmiconfig "^7.0.0"
     klona "^2.0.4"
     loader-utils "^2.0.0"
-    schema-utils "^2.7.1"
-    semver "^7.3.2"
+    schema-utils "^3.0.0"
+    semver "^7.3.4"
 
 postcss-logical@^3.0.0:
   version "3.0.0"