Minor collection of Gradle 9 fixes

This isn't enough to get Gradle 9 working locally. At the very least,
more work will be needed for changes with the shadow plugin. But all of
these changes work fine with Gradle 8 as well.

In Gradle 9.5.0 DependencyHandler (the class that powers dependencies
{}) got a project(String) method, which now shadows the method from
Project.

The AppEngine plugin pulls in WarPluginConvention, which is removed.
GoogleCloudPlatform/appengine-plugins#998 .
Disabling the auto-detection behavior for detecting the correct plugin
works around the issue.

Gradle 9 upgrades to Groovy 4, which removes groovy.util.XmlParser which
was replaced by groovy.xml.XmlParser.

Author: ejona86

all/build.gradle

@@ -38,7 +38,7 @@ for (subproject in subprojects) {
 evaluationDependsOn(':grpc-interop-testing')
 
 dependencies {
-    api subprojects.minus([project(':grpc-protobuf-lite')])
+    api subprojects.minus([project.project(':grpc-protobuf-lite')])
     implementation libraries.guava.jre // JRE required by transitive protobuf-java-util
 }
 

gae-interop-testing/gae-jdk8/build.gradle

@@ -24,7 +24,7 @@ plugins {
     id "war"
 
     id "ru.vyarus.animalsniffer"
-    id 'com.google.cloud.tools.appengine'
+    id 'com.google.cloud.tools.appengine-appenginewebxml'
 }
 
 description = 'gRPC: gae interop testing (jdk8)'
@@ -102,7 +102,7 @@ String getGaeProject() {
 }
 
 String getService(java.nio.file.Path projectPath) {
-    Node xml = new XmlParser().parse(projectPath.resolve("src/main/webapp/WEB-INF/appengine-web.xml").toFile())
+    Node xml = new groovy.xml.XmlParser().parse(projectPath.resolve("src/main/webapp/WEB-INF/appengine-web.xml").toFile())
     if (xml.service.isEmpty()) {
         return "default"
     } else {

netty/shaded/build.gradle

@@ -62,7 +62,7 @@ dependencies {
             project(':grpc-testing-proto'),
             project(':grpc-testing'),
             libraries.truth
-    shadow project(':grpc-netty').configurations.runtimeClasspath.allDependencies.matching {
+    shadow project.project(':grpc-netty').configurations.runtimeClasspath.allDependencies.matching {
         it.group != 'io.netty'
     }
     signature (libraries.signature.java) {

settings.gradle

@@ -20,7 +20,7 @@ pluginManagement {
 	// https://github.com/kt3k/coveralls-gradle-plugin/tags
         id "com.github.kt3k.coveralls" version "2.12.2"
 	// https://github.com/GoogleCloudPlatform/appengine-plugins/releases
-        id "com.google.cloud.tools.appengine" version "2.8.7"
+        id "com.google.cloud.tools.appengine-appenginewebxml" version "2.8.7"
         // https://github.com/GoogleContainerTools/jib/blob/master/jib-gradle-plugin/CHANGELOG.md
         id "com.google.cloud.tools.jib" version "3.5.4"
 	// https://github.com/google/osdetector-gradle-plugin/tags