Changes

bts: set osmo-bts sched priority to 30

Change the scheduling priority from 10 to 30, as we are currently see
osmo-bts suffering from scheduling latency in jenkins even though we
don't run other jobs at that time:

  20250425034138405 DL1C ERROR PC clock skew: elapsed_us=387574, error_us=382959 (scheduler_trx.c:449)

This testsuite currently gets executed through docker-playground and it
fetches this config from osmo-ttcn3-hacks (see
If15461240f3037c142c176fc7da745a1701ae3f8).

Related: osmo-ci I0162f7299c8e37f893ffa10ddc4c8edece29ed7f
Change-Id: I828422e2363a58ca8c19d0f1b8a1b7d4e4bc031e