[CLEANUP] Rector: Add return type to function like with return new

This applies the rule ReturnTypeFromReturnNewRector. For
Details see:
https://github.com/rectorphp/rector/blob/main/docs/rector_rules_overview.md#returntypefromreturnnewrector

Signed-off-by: Daniel Ziegenberg <daniel@ziegenberg.at>

Author: ziegenberg

src/Value/CSSFunction.php

@@ -37,13 +37,11 @@ public function __construct($sName, $aArguments, $sSeparator = ',', $iLineNo = 0
      * @param ParserState $oParserState
      * @param bool $bIgnoreCase
      *
-     * @return CSSFunction
-     *
      * @throws SourceException
      * @throws UnexpectedEOFException
      * @throws UnexpectedTokenException
      */
-    public static function parse(ParserState $oParserState, $bIgnoreCase = false)
+    public static function parse(ParserState $oParserState, $bIgnoreCase = false): CSSFunction
     {
         $mResult = $oParserState->parseIdentifier($bIgnoreCase);
         $oParserState->consume('(');