Remove code that is no longer needed because E_WARNING is ignored by …

…the error handler when the error suppression operator is used

src/Framework/Constraint/Message/MessageMatchesRegularExpression.php

@@ -9,9 +9,9 @@
  */
 namespace PHPUnit\Framework\Constraint;
 
+use function preg_match;
 use function sprintf;
 use Exception;
-use PHPUnit\Util\RegularExpression as RegularExpressionUtil;
 
 /**
  * @no-named-arguments Parameter names are not covered by the backward compatibility promise for PHPUnit
@@ -41,7 +41,7 @@ public function toString(): string
      */
     protected function matches(mixed $other): bool
     {
-        $match = RegularExpressionUtil::safeMatch($this->regularExpression, (string) $other);
+        $match = @preg_match($this->regularExpression, (string) $other);
 
         if ($match === false) {
             throw new \PHPUnit\Framework\Exception(

src/Runner/Filter/NameFilterIterator.php

@@ -19,7 +19,6 @@
 use PHPUnit\Framework\Test;
 use PHPUnit\Framework\TestCase;
 use PHPUnit\Framework\TestSuite;
-use PHPUnit\Util\RegularExpression;
 use RecursiveFilterIterator;
 use RecursiveIterator;
 
@@ -73,7 +72,7 @@ public function accept(): bool
      */
     private function setFilter(string $filter): void
     {
-        if (RegularExpression::safeMatch($filter, '') === false) {
+        if (@preg_match($filter, '') === false) {
             // Handles:
             //  * testAssertEqualsSucceeds#4
             //  * testAssertEqualsSucceeds#4-8

src/Util/ErrorHandler.php

@@ -31,7 +31,6 @@ final class ErrorHandler
 {
     private static ?self $instance = null;
     private bool $enabled          = false;
-    private bool $ignoreWarnings   = false;
 
     public static function instance(): self
     {
@@ -73,10 +72,6 @@ public function __invoke(int $errorNumber, string $errorString, string $errorFil
                 break;
 
             case E_WARNING:
-                if ($this->ignoreWarnings) {
-                    return true;
-                }
-
                 Event\Facade::emitter()->testTriggeredPhpWarning(
                     $this->testValueObjectForEvents(),
                     $errorString,
@@ -166,21 +161,6 @@ public function disable(): void
         $this->enabled = false;
     }
 
-    public function isDisabled(): bool
-    {
-        return !$this->enabled;
-    }
-
-    public function ignoreWarnings(): void
-    {
-        $this->ignoreWarnings = true;
-    }
-
-    public function doNotIgnoreWarnings(): void
-    {
-        $this->ignoreWarnings = false;
-    }
-
     /**
      * @throws Exception
      */