Disable test 2043-reference-pauses on debug-gc.

Test: 2043-reference-pauses
Change-Id: I1a4a8f6cca7aded4b61289f294d254a9d5ddedfa
diff --git a/test/knownfailures.json b/test/knownfailures.json
index 083ff80..013272f 100644
--- a/test/knownfailures.json
+++ b/test/knownfailures.json
@@ -1502,5 +1502,10 @@
         "variant": "target & ndebug & 64",
         "bug": "b/224733324",
         "description": ["segfault in VarHandle::GetMethodTypeMatchForAccessMode"]
+    },
+    {
+        "tests": ["2043-reference-pauses"],
+        "env_vars": {"ART_TEST_DEBUG_GC": "true"},
+        "description": ["Test timing out on debug gc."]
     }
 ]