Update to JVMCI 0.57.

Author: fangerer

ci.jsonnet

@@ -128,7 +128,7 @@
 
   local labsjdk8Mixin = {
     downloads +: {
-      JAVA_HOME: utils.download("labsjdk", "8u202-jvmci-0.55"),
+      JAVA_HOME: utils.download("labsjdk", "8u202-jvmci-0.57"),
       EXTRA_JAVA_HOMES : { pathlist: [utils.download("oraclejdk", "11+20")] },
     },
     environment +: {