ci/ci_run_n_monitor: make --target mandatory

There is no point running without a target, just make it mandatory and
simplify the script.

Use ".*" to run all targets.

Signed-off-by: Helen Koike <helen.koike@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25473>
1 file changed