fix: Fix jdbc tests because java.sql.Connection introduced methods with new types in JDK9

E.g. methods with `java.sql.ShardingKey`, while these methods are default, Groovy still
implements them (implementation actually invokes the interface default method).

org.gradle.api.internal.tasks.testing.TestSuiteExecutionException: Could not complete execution for Gradle Test Executor 66.
	at org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.stop(SuiteTestClassProcessor.java:65)
	...
Caused by: org.junit.platform.commons.JUnitException: TestEngine with ID 'junit-jupiter' failed to discover tests
	at org.junit.platform.launcher.core.EngineDiscoveryOrchestrator.discoverEngineRoot(EngineDiscoveryOrchestrator.java:165)
	...
Caused by: org.junit.platform.commons.JUnitException: ClassSelector [className = 'foo.bar.IastInstrumentedConnection', classLoader = sun.misc.Launcher$AppClassLoader@73d16e93] resolution failed
	at org.junit.platform.launcher.listeners.discovery.AbortOnFailureLauncherDiscoveryListener.selectorProcessed(AbortOnFailureLauncherDiscoveryListener.java:39)
	at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.resolveCompletely(EngineDiscoveryRequestResolution.java:103)
	at org.junit.platform.engine.support.discovery.EngineDiscoveryRequestResolution.run(EngineDiscoveryRequestResolution.java:83)
	...
Caused by: java.lang.NoClassDefFoundError: java/sql/ShardingKey
	at java.lang.Class.getDeclaredMethods0(Native Method)
	at java.lang.Class.privateGetDeclaredMethods(Class.java:2729)
	at java.lang.Class.privateGetPublicMethods(Class.java:2930)

Author: bric3

dd-java-agent/instrumentation/jdbc/build.gradle

@@ -86,6 +86,15 @@ tasks.named("latestDepJava11Test") {
   javaLauncher = getJavaLauncherFor(11)
 }
 
+tasks.withType(GroovyCompile).configureEach {
+  configureCompiler(
+    it,
+    8,
+    JavaVersion.VERSION_1_8,
+    "Connection has new methods with new types introduced in Java 9 that are not available on Java 8."
+    )
+}
+
 tasks.withType(Test).configureEach {
   usesService(testcontainersLimit)
 }