🌿 gardener: Disable flaking safety hub tests

These are all flaking on the android-pie-x86-rel bot.

Bug: 364523673
Change-Id: I1d30a67b5b52e4ce84644a8d0fce7d70918d46bb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5829368


Reviewed-by: Ivana Žužić <izuzic@google.com>
Commit-Queue: Ivana Žužić <izuzic@google.com>
Owners-Override: Rupert Wiser <bewise@chromium.org>
Auto-Submit: Rupert Wiser <bewise@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1350698}