[GR-44177] Use labsjdk-ee-20 in CI

* To workaround https://bugs.openjdk.org/browse/JDK-8302160
  which is not in labsjdk-ce-20 yet.

Author: eregon

ci.jsonnet

@@ -239,7 +239,8 @@ local part_definitions = {
 
     v20: with_path {
       downloads+: {
-        JAVA_HOME: common.jdks["labsjdk-ce-20"],
+        # labsjdk-ee-20, to workaround GR-44177 / https://bugs.openjdk.org/browse/JDK-8302160
+        JAVA_HOME: { name: "labsjdk", version: "ee-20.0.1+2-jvmci-23.0-b06", platformspecific: true },
       },
       environment+: {
         JT_JDK: "20",