build: update dependency postcss-loader to v6

Author: renovate-bot

package.json

@@ -194,7 +194,7 @@
     "popper.js": "^1.14.1",
     "postcss": "8.3.2",
     "postcss-import": "14.0.2",
-    "postcss-loader": "5.3.0",
+    "postcss-loader": "6.1.0",
     "postcss-preset-env": "6.7.0",
     "prettier": "^2.0.0",
     "protractor": "~7.0.0",

packages/angular_devkit/build_angular/package.json

@@ -49,7 +49,7 @@
     "parse5-html-rewriting-stream": "6.0.1",
     "postcss": "8.3.2",
     "postcss-import": "14.0.2",
-    "postcss-loader": "5.3.0",
+    "postcss-loader": "6.1.0",
     "postcss-preset-env": "6.7.0",
     "raw-loader": "4.0.2",
     "regenerator-runtime": "0.13.7",

yarn.lock

@@ -9227,14 +9227,14 @@ postcss-lab-function@^2.0.1:
     postcss "^7.0.2"
     postcss-values-parser "^2.0.0"
 
-postcss-loader@5.3.0:
-  version "5.3.0"
-  resolved "https://registry.yarnpkg.com/postcss-loader/-/postcss-loader-5.3.0.tgz#1657f869e48d4fdb018a40771c235e499ee26244"
-  integrity sha512-/+Z1RAmssdiSLgIZwnJHwBMnlABPgF7giYzTN2NOfr9D21IJZ4mQC1R2miwp80zno9M4zMD/umGI8cR+2EL5zw==
+postcss-loader@6.1.0:
+  version "6.1.0"
+  resolved "https://registry.yarnpkg.com/postcss-loader/-/postcss-loader-6.1.0.tgz#13c800a00b3c7d434a1319a73d85e2df0714cdde"
+  integrity sha512-yA/cXBfACkthZNA2hQxOnaReVfQ6uLmvbEDQzNafpbK40URZJvP/28dL1DG174Gvz3ptkkHbbwDBCh+gXR94CA==
   dependencies:
     cosmiconfig "^7.0.0"
     klona "^2.0.4"
-    semver "^7.3.4"
+    semver "^7.3.5"
 
 postcss-logical@^3.0.0:
   version "3.0.0"