Arm backend: Add non-interactive in git hook (#10712)

The pre-push script is a nice to have script as a git hook for your work
with the arm backend.

In fact, it is so nice that we would like it to be part of CI jobs but
to make that happen it needs to be non-interactive.

This patch adds support for launching the script and never ending up in
a scenario where the user has to interact with it.

Signed-off-by: per.held@arm.com