Update trials factors for O4b

Update the trials factor for O4b.

Currently, this MR assumes that the group.search.pipelines running are (in addition to Raven of course)

Burst thresholds (2 pipelines)

• burst.allsky.cwb
• burst.allsky.olib

CBC thresholds (4 pipelines)

• burst.bbh.cwb
• cbc.allsky.gstlal
• cbc.allsky.mbta
• cbc.allsky.pycbc