Build(deps): Bump postcss-less from 3.1.4 to 4.0.0 (#9471)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: fisker <lionkay@gmail.com>

src/language-css/parser-postcss.js

@@ -302,7 +302,6 @@ function parseNestedCSS(node, options) {
 
     // Custom properties looks like declarations
     if (
-      (options.parser === "css" || options.parser === "scss") &&
       node.type === "css-decl" &&
       typeof node.prop === "string" &&
       node.prop.startsWith("--") &&
@@ -325,7 +324,9 @@ function parseNestedCSS(node, options) {
         let parse;
         if (options.parser === "scss") {
           parse = parseScss;
-        } else if (options.parser === "css") {
+        } else if (options.parser === "less") {
+          parse = parseLess;
+        } else {
           parse = parseCss;
         }
         let ast;