[rust] Disable signal code check on Rust crash

This is a test which intentionally crashes the renderer in Rust code. We
previously checked which signal code was received, but this seems to
depend upon whether the sandbox is enabled (and possibly whether
sanitizers are enabled).

For now, remove the check, while we investigate, in order to make the
test bots go green.

Bug: 1368726, 1451958
Change-Id: Idb427eced0267856afbf941fe354fee275b4fefc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4594482
Owners-Override: Anders Hartvoll Ruud <andruud@google.com>
Reviewed-by: Dominik Röttsches <drott@chromium.org>
Commit-Queue: Dominik Röttsches <drott@chromium.org>
Auto-Submit: Adrian Taylor <adetaylor@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1154312}