MDL-65759 library: Update php-css-parser to 8.3.0

lib/php-css-parser/CSSList/Document.php

@@ -2,6 +2,8 @@
 
 namespace Sabberworm\CSS\CSSList;
 
+use Sabberworm\CSS\Parsing\ParserState;
+
 /**
  * The root CSSList of a parsed file. Contains all top-level css contents, mostly declaration blocks, but also any @-rules encountered.
  */
@@ -14,6 +16,12 @@ class Document extends CSSBlockList {
 		parent::__construct($iLineNo);
 	}
 
+	public static function parse(ParserState $oParserState) {
+		$oDocument = new Document($oParserState->currentLine());
+		CSSList::parseList($oParserState, $oDocument);
+		return $oDocument;
+	}
+
 	/**
 	 * Gets all DeclarationBlock objects recursively.
 	 */