Throw within utils.py's run instead of propagating error code

None of the scenarios in which we make use of utils.py's run we can
recover from that method failing. So, instead of propagating the error
code, simply let subprocess throw. This improves readability by
simplifying the code flow.

Change-Id: Id0588f19a80214eaf90fb9d5e2e684c1ca93e7a5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6308824
Reviewed-by: Mohannad Farrag <aymanm@google.com>
Commit-Queue: Stefano Duo <stefanoduo@google.com>
Cr-Commit-Position: refs/heads/main@{#1447781}