[test] Skip flaky test under tsan

BUG=v8:5807
NOTRY=true
TBR=clemensh@chromium.org,ahaas@chromium.org

Review-Url: https://codereview.chromium.org/2620653002
Cr-Commit-Position: refs/heads/master@{#42133}

test/mjsunit/mjsunit.status

@@ -166,6 +166,9 @@
   # TODO(vogelheim): big-object-literal exceeds the stack in debug builds,
   #                  which makes the test useless.
   'big-object-literal': [PASS, ['mode == debug', SKIP]],
+
+  # BUG(v8:5807): Flaky data race.
+  'wasm/embenchen/fannkuch': [PASS, ['tsan', SKIP]],
 }],  # ALWAYS
 
 ['novfp3 == True', {