[test] Mark slow tests

No-Try: true
Bug: v8:10923
Change-Id: I254a6190aa7aad69a7e11c58e78429a45eec9962
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2414208
Auto-Submit: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Sathya Gunasekaran  <gsathya@chromium.org>
Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69946}

test/mjsunit/mjsunit.status

@@ -132,6 +132,7 @@
   'harmony/futex': [PASS, SLOW],
   'harmony/regexp-property-script-extensions': [PASS, SLOW],
   'ignition/regress-672027': [PASS, SLOW],
+  'large-object-literal-slow-elements': [PASS, SLOW],
   'math-floor-of-div': [PASS, SLOW],
   'md5': [PASS, SLOW],
   'readonly': [PASS, SLOW],
@@ -142,6 +143,7 @@
   'regress/regress-crbug-808192': [PASS, SLOW, NO_VARIANTS, ['arch not in (ia32, x64)', SKIP]],
   'regress/regress-crbug-918301': [PASS, SLOW, NO_VARIANTS, ['mode != release or dcheck_always_on', SKIP], ['(arch == arm or arch == arm64) and simulator_run', SKIP], ['tsan', SKIP]],
   'regress/wasm/regress-810973': [PASS, SLOW],
+  'sealed-array-reduce': [PASS, SLOW],
   'string-replace-gc': [PASS, SLOW],
   'wasm/asm-wasm-f32': [PASS, SLOW],
   'wasm/asm-wasm-f64': [PASS, SLOW],
@@ -300,7 +302,6 @@
   # Slow tests.
   'array-constructor': [PASS, SLOW],
   'json': [PASS, SLOW],
-  'large-object-literal-slow-elements': [PASS, SLOW],
   'harmony/sharedarraybuffer-worker-gc-stress': [PASS, SLOW],
 
   # BUG(v8:4779): Crashes flakily with stress mode on arm64.