[test] Disable flag --stress-scavenge for pretenure deopt test

With --stress-scavenge it is possible that we don't have a memento for
the object we are interested in anymore, making the test useless.

Bug: v8:11701
Change-Id: I05984de33dc0c21d01023ebaa4ceebacfb63cc84
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2851889
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Auto-Submit: Patrick Thier <pthier@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74218}

test/mjsunit/compiler/deopt-pretenure.js

@@ -4,6 +4,7 @@
 
 // Flags: --allow-natives-syntax --opt --no-always-opt
 // Flags: --allocation-site-pretenuring --stress-gc-during-compilation
+// Flags: --stress-scavenge=0
 // Flags: --max-optimized-bytecode-size=132000
 
 function CheckOptimizationStatus(func, expectedOptimizationStatus) {