use container registry image with generic 8 version tag

Author: ddsharpe

tests/src/test/java/com/oracle/weblogic/imagetool/tests/ITImagetool.java

@@ -897,7 +897,7 @@ void createImageWithServerJRE(TestInfo testInfo) throws Exception {
         String tagName = build_tag + ":" + getMethodName(testInfo);
         String command = new CreateCommand()
             .tag(tagName)
-            .fromImage("container-registry.oracle.com/java/serverjre:8u271")
+            .fromImage("container-registry.oracle.com/java/serverjre:8")
             .build();
 
         try (PrintWriter out = getTestMethodWriter(testInfo)) {