[Gradle] Wire java toolchain plugin into integration tests (elastic#125347) (elastic#125467)

* [Gradle] Wire java toolchain plugin into integration tests

This addresses transient issues we see in the integration tests where previously resolved jdk toolchain
is not available. See https://gradle-enterprise.elastic.co/s/66msrp7n2nsdy/tests/task/:build-tools-internal:integTest/details/org.elasticsearch.gradle.internal.test.rest.LegacyYamlRestTestPluginFuncTest/yamlRestTest%20executes%20and%20copies%20api%20and%20tests%20to%20correct%20source%20set\?top-execution\=1 for example

* Fix fix

Author: breskeby

build-tools-internal/src/integTest/groovy/org/elasticsearch/gradle/fixtures/AbstractGradleInternalPluginFuncTest.groovy

@@ -20,6 +20,22 @@ abstract class AbstractGradleInternalPluginFuncTest extends AbstractJavaGradleFu
         plugins {
             id 'elasticsearch.java-toolchain'
         }
+
+        toolchainManagement {
+          jvm {
+            javaRepositories {
+              repository('bundledOracleOpendJdk') {
+                resolverClass = org.elasticsearch.gradle.internal.toolchain.OracleOpenJdkToolchainResolver
+              }
+              repository('adoptiumJdks') {
+                resolverClass = org.elasticsearch.gradle.internal.toolchain.AdoptiumJdkToolchainResolver
+              }
+              repository('archivedOracleJdks') {
+                resolverClass = org.elasticsearch.gradle.internal.toolchain.ArchivedOracleJdkToolchainResolver
+              }
+            }
+          }
+        }
         """ + settingsFile.text
 
         buildFile << """