Revert "[test] Skip flaky test under tsan"

This reverts commit b606e1b6.

No longer flakes since
https://crrev.com/f6929084821d4f021b2c2768c9856472ffa42623

BUG=v8:5807
TBR=machenbach@chromium.org

Review-Url: https://codereview.chromium.org/2782173002
Cr-Commit-Position: refs/heads/master@{#44234}

test/mjsunit/mjsunit.status

@@ -181,9 +181,6 @@
   #                  which makes the test useless.
   'big-object-literal': [PASS, ['mode == debug', SKIP]],
 
-  # BUG(v8:5807): Flaky data race.
-  'wasm/embenchen/fannkuch': [PASS, ['tsan', SKIP]],
-
   # BUG(v8:5778): These fail with --future, which we are about to turn on.
   # Investigate.
   'regress/regress-105': [SKIP],