chore(deps): update dependency postcss-loader to v6 (#203)

Co-authored-by: Renovate Bot <bot@renovateapp.com>

packages/webpack/package.json

@@ -31,7 +31,7 @@
     "pify": "^5.0.0",
     "postcss": "^8.3.4",
     "postcss-import-resolver": "^2.0.0",
-    "postcss-loader": "^5.3.0",
+    "postcss-loader": "^6.1.0",
     "style-resources-loader": "^1.4.1",
     "time-fix-plugin": "^2.0.7",
     "ufo": "^0.7.5",

yarn.lock

@@ -2045,7 +2045,7 @@ __metadata:
     pify: ^5.0.0
     postcss: ^8.3.4
     postcss-import-resolver: ^2.0.0
-    postcss-loader: ^5.3.0
+    postcss-loader: ^6.1.0
     style-resources-loader: ^1.4.1
     time-fix-plugin: ^2.0.7
     ufo: ^0.7.5
@@ -11281,17 +11281,17 @@ __metadata:
   languageName: node
   linkType: hard
 
-"postcss-loader@npm:^5.3.0":
-  version: 5.3.0
-  resolution: "postcss-loader@npm:5.3.0"
+"postcss-loader@npm:^6.1.0":
+  version: 6.1.0
+  resolution: "postcss-loader@npm:6.1.0"
   dependencies:
     cosmiconfig: ^7.0.0
     klona: ^2.0.4
-    semver: ^7.3.4
+    semver: ^7.3.5
   peerDependencies:
     postcss: ^7.0.0 || ^8.0.1
     webpack: ^5.0.0
-  checksum: fd7a1a673b0e8f238392b3d449f2727767522febb2f60bfc9bb5cd4e373b07ba8df621f4e2fad92bf085765dcdea0f049497ae799ce1c9f1a592820275cc7e65
+  checksum: 4b85ab6c56668a4e17ddc5fb617cae4c63813c2d630769a5a510af7d5667c10c9668c51c56dbde67b9d56eda1db8d5746af8929d8962fee287ffb54631d013cd
   languageName: node
   linkType: hard