Fix tests on JDK 21

Issue gh-12790
Issue gh-13811

web/src/test/java/org/springframework/security/web/util/TextEscapeUtilsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -62,7 +62,7 @@ public class TextEscapeUtilsTests {
 
 	@Test
 	public void undefinedSurrogatePairIsIgnored() {
-		assertThat(TextEscapeUtils.escapeEntities("abc\uD888\uDC00a")).isEqualTo("abca");
+		assertThat(TextEscapeUtils.escapeEntities("abc\uDBFF\uDFFFa")).isEqualTo("abca");
 	}
 
 }