tests: gate ReflectionProperty::setAccessible()

Author: justlevine

tests/phpunit/tests/ai-client/wpAiClientPrompt.php

@@ -43,7 +43,9 @@ public function test_returns_error_builder_when_ai_not_supported() {
 		// Check the $error prop is a real WP_Error with the expected message.
 		$reflection = new ReflectionClass( $builder );
 		$error_prop = $reflection->getProperty( 'error' );
-		$error_prop->setAccessible( true );
+		if ( PHP_VERSION_ID < 80100 ) {
+			$error_prop->setAccessible( true );
+		}
 		$error = $error_prop->getValue( $builder );
 
 		$this->assertInstanceOf( WP_Error::class, $error );