postcss.config.js: remove arrow return (#32235)

build/postcss.config.js

@@ -1,16 +1,18 @@
 'use strict'
 
-module.exports = ctx => ({
-  map: ctx.file.dirname.includes('examples') ?
-    false :
-    {
-      inline: false,
-      annotation: true,
-      sourcesContent: true
-    },
-  plugins: {
-    autoprefixer: {
-      cascade: false
+module.exports = ctx => {
+  return {
+    map: ctx.file.dirname.includes('examples') ?
+      false :
+      {
+        inline: false,
+        annotation: true,
+        sourcesContent: true
+      },
+    plugins: {
+      autoprefixer: {
+        cascade: false
+      }
     }
   }
-})
+}