Skip mjsunit/compiler/inlined-call-polymorphic under stress_concurrent_inlining

It's flaky in that config, and the failures are not considered actionable.

Bug: v8:12267
Change-Id: Ibc020cd7d28ddda431ec5f79f3c1952a14ffbfa9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3763582
Auto-Submit: Adam Klein <adamk@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#81728}

test/mjsunit/mjsunit.status

@@ -1547,6 +1547,12 @@
   'baseline/*': [SKIP],
 }],  # variant == no_lfa or variant == stress_concurrent_inlining
 
+##############################################################################
+['variant == stress_concurrent_inlining', {
+  # Flaky under this variant, skipping per https://crbug.com/v8/12267#c4
+  'compiler/inlined-call-polymorphic': [SKIP],
+}],  # variant == stress_concurrent_inlining
+
 ##############################################################################
 ['variant == experimental_regexp', {
   'regress/regress-779407': [SKIP],