Modify the gradle.properties to specify the other JDK

Also a small change in Setup.kt

Author: jwren

gradle.properties

@@ -12,3 +12,6 @@ javaVersion=21
 kotlin.stdlib.default.dependency=false
 org.gradle.parallel=true
 org.gradle.jvmargs=-Xms1024m -Xmx4048m
+
+org.gradle.java.installations.auto-detect=false
+org.gradle.java.installations.dirs=/opt/jdk-21 # Replace with the actual path where JDK 21 is installed by the GitHub Actions runner

testSrc/integration/io/flutter/integrationTest/Setup.kt

@@ -16,6 +16,7 @@ import com.intellij.ide.starter.models.TestCase
 import com.intellij.ide.starter.path.GlobalPaths
 import com.intellij.ide.starter.plugins.PluginConfigurator
 import com.intellij.ide.starter.project.NoProject
+import com.intellij.ide.starter.project.ProjectInfoSpec
 import com.intellij.ide.starter.runner.Starter
 import com.intellij.ide.starter.utils.Git
 import com.intellij.openapi.util.SystemInfo
@@ -100,9 +101,9 @@ class Setup {
      *
      * @throws IllegalStateException if required system properties are not set
      */
-    fun setupTestContext(hyphenateWithClass: String, ideInfo: IdeInfo): IDETestContext {
+    fun setupTestContext(hyphenateWithClass: String, ideInfo: IdeInfo, projectInfoSpec: ProjectInfoSpec = NoProject): IDETestContext {
 
-      val testCase = TestCase(ideInfo, NoProject)
+      val testCase = TestCase(ideInfo, projectInfoSpec)
 
       return Starter.newContext(testName = hyphenateWithClass, testCase = testCase).apply {
         // Install the plugin that was built by the buildPlugin task