Fix ignored spock build tools integ tests (elastic#71769)

Gradle 7.0 forced us to update to spock2 because we need a groovy 3 compatible
spock framework version. Spock2 requires junit5 to be executed. We use the junit5 platform
but provide the vintage runner to be able to execute junit4 implemented IT tests too

Author: breskeby

buildSrc/build.gradle

@@ -112,9 +112,24 @@ dependencies {
   testImplementation 'com.github.tomakehurst:wiremock-jre8-standalone:2.23.2'
   testImplementation 'org.mockito:mockito-core:1.9.5'
   testImplementation "org.hamcrest:hamcrest:${props.getProperty('hamcrest')}"
-  integTestImplementation('org.spockframework:spock-core:2.0-M5-groovy-3.0') {
+
+  integTestImplementation(platform("org.junit:junit-bom:${props.getProperty('junit5')}"))
+  integTestImplementation("org.junit.jupiter:junit-jupiter") {
+    because 'allows to write and run Jupiter tests'
+  }
+  integTestRuntimeOnly("org.junit.vintage:junit-vintage-engine") {
+    because 'allows JUnit 3 and JUnit 4 tests to run'
+  }
+
+  integTestRuntimeOnly("org.junit.platform:junit-platform-launcher") {
+    because 'allows tests to run from IDEs that bundle older version of launcher'
+  }
+
+  integTestImplementation platform("org.spockframework:spock-bom:2.0-M5-groovy-3.0")
+  integTestImplementation("org.spockframework:spock-core") {
     exclude module: "groovy"
   }
+  integTestImplementation "org.spockframework:spock-junit4"  // you can remove this if your code does not rely on old JUnit 4 rules
   integTestImplementation "org.xmlunit:xmlunit-core:2.8.2"
 }
 
@@ -230,6 +245,7 @@ if (project != rootProject) {
     systemProperty 'test.version_under_test', version
     testClassesDirs = sourceSets.integTest.output.classesDirs
     classpath = sourceSets.integTest.runtimeClasspath
+    useJUnitPlatform()
   }
   tasks.named("check").configure { dependsOn("integTest") }
 

buildSrc/src/integTest/groovy/org/elasticsearch/gradle/PublishPluginFuncTest.groovy

@@ -39,7 +39,7 @@ class PublishPluginFuncTest extends AbstractGradleFuncTest {
         file("build/distributions/hello-world-1.0.pom").exists()
         assertXmlEquals(file("build/distributions/hello-world-1.0.pom").text, """
             <project xmlns="http://maven.apache.org/POM/4.0.0" 
-                     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" 
+                     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd" 
                      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
               <modelVersion>4.0.0</modelVersion>
               <groupId>org.acme</groupId>
@@ -96,7 +96,7 @@ class PublishPluginFuncTest extends AbstractGradleFuncTest {
         file("build/distributions/hello-world-plugin-1.0.pom").exists()
         assertXmlEquals(file("build/distributions/hello-world-plugin-1.0.pom").text, """
             <project xmlns="http://maven.apache.org/POM/4.0.0" 
-                     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" 
+                     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd" 
                      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
               <modelVersion>4.0.0</modelVersion>
               <groupId>org.acme</groupId>
@@ -141,7 +141,7 @@ class PublishPluginFuncTest extends AbstractGradleFuncTest {
         file("build/distributions/hello-world-plugin-1.0.pom").exists()
         assertXmlEquals(file("build/distributions/hello-world-plugin-1.0.pom").text, """
             <project xmlns="http://maven.apache.org/POM/4.0.0" 
-                     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" 
+                     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd" 
                      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
               <modelVersion>4.0.0</modelVersion>
               <groupId>org.acme</groupId>
@@ -202,7 +202,7 @@ class PublishPluginFuncTest extends AbstractGradleFuncTest {
         file("build/distributions/hello-world-1.0.pom").exists()
         assertXmlEquals(file("build/distributions/hello-world-1.0.pom").text, """
             <project xmlns="http://maven.apache.org/POM/4.0.0" 
-                     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" 
+                     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd" 
                      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
               <modelVersion>4.0.0</modelVersion>
               <groupId>org.acme</groupId>

buildSrc/version.properties

@@ -34,6 +34,7 @@ bouncycastle=1.64
 # test dependencies
 randomizedrunner  = 2.7.7
 junit             = 4.12
+junit5            = 5.7.1
 httpclient        = 4.5.10
 httpcore          = 4.4.12
 httpasyncclient   = 4.1.4