Fix compilation error with Tomcat 10

There's no setter for the max header size in Tomcat 10 as it's now
inherited from the underlying HTTP 1.1 protocol. The test that
was merged forwards from 2.7.x is retained to verify that this is
the case.

See gh-31330

Author: wilkinsona

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/TomcatWebServerFactoryCustomizer.java

@@ -280,11 +280,6 @@ private void customizeMaxHttpHeaderSize(ConfigurableTomcatWebServerFactory facto
 			if (handler instanceof AbstractHttp11Protocol) {
 				AbstractHttp11Protocol protocol = (AbstractHttp11Protocol) handler;
 				protocol.setMaxHttpHeaderSize(maxHttpHeaderSize);
-				for (UpgradeProtocol upgradeProtocol : protocol.findUpgradeProtocols()) {
-					if (upgradeProtocol instanceof Http2Protocol) {
-						((Http2Protocol) upgradeProtocol).setMaxHeaderSize(maxHttpHeaderSize);
-					}
-				}
 			}
 		});
 	}