[TASK] Use native type declarations in Parser (#1140)

Part of #811

Author: oliverklee

CHANGELOG.md

@@ -32,7 +32,7 @@ Please also have a look at our
 - Make all non-private properties `@internal` (#886)
 - Use more native type declarations and strict mode
   (#641, #772, #774, #778, #804, #841, #873, #875, #891, #922, #923, #933, #958,
-  #964, #967, #1000, #1044, #1134, #1136, #1137, #1139)
+  #964, #967, #1000, #1044, #1134, #1136, #1137, #1139, #1140)
 - Add visibility to all class/interface constants (#469)
 
 ### Deprecated

src/Parser.php

@@ -22,7 +22,7 @@ class Parser
      * @param string $text the complete CSS as text (i.e., usually the contents of a CSS file)
      * @param int<1, max> $lineNumber the line number (starting from 1, not from 0)
      */
-    public function __construct($text, ?Settings $parserSettings = null, int $lineNumber = 1)
+    public function __construct(string $text, ?Settings $parserSettings = null, int $lineNumber = 1)
     {
         if ($parserSettings === null) {
             $parserSettings = Settings::create();