Tests: remove work-arounds for @requires tags

PHPUnit supports the `@requires OSFAMILY ...` syntax since PHPUnit 7.

As this new type doesn't allow for negation, the `@requires     OS ^(?!WIN).*` for the `PrepareForOutputTest::testPrepareForOutput()` method needs to remain as it should run when _not_ on Windows.

Author: jrfnl

tests/Core/Ruleset/RuleInclusionAbsoluteWindowsTest.php

@@ -17,7 +17,7 @@
  * Tests for the \PHP_CodeSniffer\Ruleset class using a Windows-style absolute path to include a sniff.
  *
  * @covers   \PHP_CodeSniffer\Ruleset
- * @requires OS ^WIN.*.
+ * @requires OSFAMILY Windows
  * @group    Windows
  */
 final class RuleInclusionAbsoluteWindowsTest extends TestCase

tests/Core/Util/Common/PrepareForOutputTest.php

@@ -49,7 +49,7 @@ public function testPrepareForOutput($content, $exclude, $expected, $expectedWin
      * @param string   $expected    Expected function output (unused in this test).
      * @param string   $expectedWin Expected function output on Windows.
      *
-     * @requires     OS ^WIN.*.
+     * @requires     OSFAMILY Windows
      * @dataProvider dataPrepareForOutput
      *
      * @return void