[test] Mark a Wasm test as slow on TSAN

Bug: v8:11780
Change-Id: I646092d7e54893ff065db0cf1ce72533617ea38d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2968408
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Auto-Submit: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75221}

test/mjsunit/mjsunit.status

@@ -630,6 +630,8 @@
   'regress/regress-500980': [PASS, SLOW],
   'regress/regress-crbug-941743': [PASS, SLOW],
   'wasm/shared-memory-worker-stress': [PASS, SLOW],
+  # https://crbug.com/v8/11780 - Flakily times out on TSAN.
+  'wasm/memory_1gb_oob': [PASS, SLOW],
 
   # BUG(v8:9506): times out.
   'wasm/shared-memory-worker-explicit-gc-stress': [SKIP],