Make coincidence FAR synchronous

This fixes a race condition where the coincidence FAR is made asynchronous with the rest of the RAVEN pipeline, which means it gets failed to be downloaded later in the pipeline (error: https://sentry.io/organizations/ligo-caltech/issues/1164176998/?query=is%3Aunresolved; see where called in raven pipeline and where attempted to be downloaded later). This change makes the raven pipeline wait for this calculation to be finished and uploaded before trying to download later.