Add --concurrent-recompilation to a test's Flags

One of the subtests relies on that.

R=jgruber@chromium.org

Bug: v8:12069
Change-Id: I648a766baf4d977f4df607754f666bd9e9102168
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3086473
Commit-Queue: Georg Neis <neis@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Auto-Submit: Georg Neis <neis@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#76218}

test/mjsunit/const-dict-tracking.js

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 //
 // Flags: --allow-natives-syntax --opt --no-always-opt
-// Flags: --no-stress-flush-code
+// Flags: --no-stress-flush-code --concurrent-recompilation
 //
 // Tests tracking of constness of properties stored in dictionary
 // mode prototypes.