Revert "Merge branch '3.1.x'"

See gh-36092

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/UndertowWebServerFactoryCustomizerTests.java

@@ -103,24 +103,6 @@ class UndertowWebServerFactoryCustomizerTests {
 		assertThat(boundServerOption(UndertowOptions.MAX_HEADER_SIZE)).isNull();
 	}
 
-	@Test
-	void customMaxHttpRequestHeaderSize() {
-		bind("server.max-http-request-header-size=2048");
-		assertThat(boundServerOption(UndertowOptions.MAX_HEADER_SIZE)).isEqualTo(2048);
-	}
-
-	@Test
-	void customMaxHttpRequestHeaderSizeIgnoredIfNegative() {
-		bind("server.max-http-request-header-size=-1");
-		assertThat(boundServerOption(UndertowOptions.MAX_HEADER_SIZE)).isNull();
-	}
-
-	@Test
-	void customMaxHttpRequestHeaderSizeIgnoredIfZero() {
-		bind("server.max-http-request-header-size=0");
-		assertThat(boundServerOption(UndertowOptions.MAX_HEADER_SIZE)).isNull();
-	}
-
 	@Test
 	void customMaxHttpPostSize() {
 		bind("server.undertow.max-http-post-size=256");