ci/lava: Flexibilize section marker regexes

ci/lava: Flexibilize section marker regexes

In some jobs, such as
https://gitlab.freedesktop.org/gallo/mesa/-/jobs/24904100, the kmsg is
interleaved with stderr/stdout in serial console, making it difficult to
confidently find the log messages to detect when the DUT is booting,
when the DUT is running etc.

Luckily, LAVA sends redundant messages about their signals. We can use
them to mitigate the chance of missing an interleaved message by being
more open to different messages, using the regex on both `debug` and
`target` LAVA log levels.

Signed-off-by: Guilherme Gallo <guilherme.gallo@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16323>