Disable test 660 for debuggable

Debuggable prevents AOT initialization of classes.

Bug: 70735003
Test: test/testrunner/run_build_test_target.py -j50 art-jit

Change-Id: Iec862c287499ffc68e0ea65a9ca05dbc4bc79316
diff --git a/test/knownfailures.json b/test/knownfailures.json
index cb0fc0f..bd32647 100644
--- a/test/knownfailures.json
+++ b/test/knownfailures.json
@@ -738,10 +738,11 @@
     },
     {
         "tests": "660-clinit",
-        "variant": "no-image | no-prebuild | jvmti-stress | redefine-stress | interp-ac",
+        "variant": "no-image | no-prebuild | jvmti-stress | redefine-stress | interp-ac | debuggable",
         "description": ["Tests <clinit> for app images, which --no-image, --no-prebuild, ",
                         "and --redefine-stress do not create. Also avoid for ",
-                        "verify-soft-fail (interp-ac) since it prevents initialization."]
+                        "verify-soft-fail (interp-ac) and debuggable since they prevent ",
+                        "initialization."]
     },
     {
         "tests": ["961-default-iface-resolution-gen",