Twenty Nineteen: Update PostCSS to version 8.x.

This updates the build processes within Twenty Nineteen to use the latest major version of PostCSS, 8.x.

There are no changes to any built files as a result of these updates.

Props desrosj, peterwilsoncc.
Fixes #57554.
Built from https://develop.svn.wordpress.org/trunk@55458


git-svn-id: http://core.svn.wordpress.org/trunk@54991 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-content/themes/twentynineteen/package.json

@@ -12,8 +12,9 @@
     "chokidar-cli": "^3.0.0",
     "node-sass": "^8.0.0",
     "npm-run-all": "^4.1.5",
-    "postcss-cli": "^7.1.2",
-    "postcss-focus-within": "^4.0.0",
+    "postcss": "^8.4.21",
+    "postcss-cli": "^10.1.0",
+    "postcss-focus-within": "^7.0.2",
     "rtlcss": "^4.0.0"
   },
   "rtlcssConfig": {
@@ -23,7 +24,8 @@
       "clean": true,
       "greedy": false,
       "processUrls": false,
-      "stringMap": []
+      "stringMap": [],
+      "disablePolyfillReadyClass": true
     },
     "plugins": [],
     "map": false

wp-content/themes/twentynineteen/postcss.config.js

@@ -8,6 +8,8 @@ module.exports = {
 
 module.exports = {
     plugins: [
-        postcssFocusWithin(/* pluginOptions */)
+        postcssFocusWithin({
+            disablePolyfillReadyClass: true
+        })
     ]
 };

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.2-beta4-55457';
+$wp_version = '6.2-beta4-55458';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.