[test] Skip flaky test for turbofan always-opt and gc-stress

BUG=v8:5053
TBR=bmeurer@chromium.org
NOTRY=true

Review-Url: https://codereview.chromium.org/2024583002
Cr-Commit-Position: refs/heads/master@{#36571}

test/mjsunit/mjsunit.status

@@ -413,6 +413,9 @@
 
   # BUG(v8:4779): Crashes flakily with stress mode on arm64.
   'array-splice': [PASS, SLOW, ['arch == arm64', FAST_VARIANTS]],
+
+  # BUG(v8:5053).
+  'wasm/embenchen/fasta': [PASS, FAST_VARIANTS],
 }],  # 'gc_stress == True'
 
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