Issue #3500293 by nicxvan, dww, catch: Add headroom to the navigation performance test

core/modules/navigation/tests/src/FunctionalJavascript/PerformanceTest.php

@@ -80,7 +80,7 @@ public function testLogin(): void {
     $this->assertSame(0, $performance_data->getCacheTagInvalidationCount());
     $this->assertSame(1, $performance_data->getStyleSheetCount());
     $this->assertSame(2, $performance_data->getScriptCount());
-    $this->assertLessThan(90000, $performance_data->getStylesheetBytes());
+    $this->assertLessThan(90200, $performance_data->getStylesheetBytes());
     $this->assertLessThan(220000, $performance_data->getScriptBytes());
 
     // Check that the navigation toolbar is cached without any high-cardinality