[TASK] Add native type declarations for DeclarationBlock (#1193)

Part of #811

Author: oliverklee

CHANGELOG.md

@@ -35,7 +35,7 @@ Please also have a look at our
   (#641, #772, #774, #778, #804, #841, #873, #875, #891, #922, #923, #933, #958,
   #964, #967, #1000, #1044, #1134, #1136, #1137, #1139, #1140, #1141, #1145,
   #1162, #1163, #1166, #1172, #1174, #1178, #1179, #1181, #1183, #1184, #1186,
-  #1187, #1190, #1192)
+  #1187, #1190, #1192, #1193)
 - Add visibility to all class/interface constants (#469)
 
 ### Deprecated

src/RuleSet/DeclarationBlock.php

@@ -30,16 +30,14 @@ class DeclarationBlock extends RuleSet
     private $selectors = [];
 
     /**
-     * @param CSSList|null $list
-     *
      * @return DeclarationBlock|false
      *
      * @throws UnexpectedTokenException
      * @throws UnexpectedEOFException
      *
      * @internal since V8.8.0
      */
-    public static function parse(ParserState $parserState, $list = null)
+    public static function parse(ParserState $parserState, ?CSSList $list = null)
     {
         $comments = [];
         $result = new DeclarationBlock($parserState->currentLine());
@@ -77,11 +75,10 @@ public static function parse(ParserState $parserState, $list = null)
 
     /**
      * @param array<Selector|string>|string $selectors
-     * @param CSSList|null $list
      *
      * @throws UnexpectedTokenException
      */
-    public function setSelectors($selectors, $list = null): void
+    public function setSelectors($selectors, ?CSSList $list = null): void
     {
         if (\is_array($selectors)) {
             $this->selectors = $selectors;