Use runtime java home for third party audit task (#91412) (#91432)

We actually do indeed need to use the runtime Java for this task
because depending on the target version, we may be loading classes
for a later Java version. For example, if we use dependencies that are
MR jars, then we in fact do load different classes depending on the
runtime Java version. To test this properly then we need to use the
target Java version to actually execute the task so it can both load
the newer classes, and any classes from any newer APIs present in the
later Java version.

Author: mark-vieira

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/precommit/ThirdPartyAuditPrecommitPlugin.java

@@ -16,7 +16,6 @@
 import org.gradle.api.Task;
 import org.gradle.api.artifacts.Configuration;
 import org.gradle.api.tasks.TaskProvider;
-import org.gradle.internal.jvm.Jvm;
 
 import java.nio.file.Path;
 
@@ -61,7 +60,9 @@ public TaskProvider<? extends Task> createTask(Project project) {
                 return dep.getGroup() != null && dep.getGroup().startsWith("org.elasticsearch") == false;
             }));
             t.dependsOn(resourcesTask);
-            t.setJavaHome(Jvm.current().getJavaHome().getPath());
+            if (BuildParams.getIsRuntimeJavaHomeSet()) {
+                t.setJavaHome(BuildParams.getRuntimeJavaHome().getPath());
+            }
             t.getTargetCompatibility().set(project.provider(BuildParams::getRuntimeJavaVersion));
             t.setSignatureFile(resourcesDir.resolve("forbidden/third-party-audit.txt").toFile());
             t.getJdkJarHellClasspath().from(jdkJarHellConfig);