Disable flaky ShowTooltipFromIFrameWithKeyboard test on all platforms

TooltipBrowsertest.ShowTooltipFromIFrameWithKeyboard has already been
disabled on ChromeOS and Windows, but there is occasional flakiness in
Chromium and Edge in Linux as well.

Several other tests in this test suite have been disabled for ChromeOS,
Windows, and Linux.

Test history: https://ci.chromium.org/ui/test/chromium/ninja%3A%2F%2Fchrome%2Ftest%3Ainteractive_ui_tests%2FTooltipBrowserTest.ShowTooltipFromIFrameWithKeyboard

Bug: 40768202
Change-Id: I5fbf3020fa2549b16038454f5ca31314f67e540e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5601919


Reviewed-by: Benjamin Beaudry <benjamin.beaudry@microsoft.com>
Commit-Queue: Evelynn Kaplan <evelynn.kaplan@microsoft.com>
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Alison Maher <almaher@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#1312944}