Use a more relaxed AliasCheck for CI on Windows

ContextHandler.ApproveAliases has been deprecated. We tried to
replace it with AllowedResourceAliasChecker but it does not
behave in the same way and causes CI failures on Windows.
ContextHandler.ApproveAliases always returns true so we should
hardcode our own implementation that does the same.

Closes gh-30045

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-jetty-jsp/src/test/java/smoketest/jetty/jsp/SampleWebJspApplicationTests.java

@@ -16,7 +16,6 @@
 
 package smoketest.jetty.jsp;
 
-import org.eclipse.jetty.server.AllowedResourceAliasChecker;
 import org.eclipse.jetty.server.handler.ContextHandler;
 import org.junit.jupiter.api.Test;
 
@@ -60,7 +59,7 @@ class SampleWebJspApplicationTests {
 		JettyServerCustomizer jettyServerCustomizer() {
 			return (server) -> {
 				ContextHandler handler = (ContextHandler) server.getHandler();
-				handler.addAliasCheck(new AllowedResourceAliasChecker(handler));
+				handler.addAliasCheck((path, resource) -> true);
 			};
 		}