IndexError: list index out of range

[sentry]

Sentry Issue: CHRONOGRAPHER-H

CancelledError: 
  File "asyncio/queues.py", line 166, in get
    await getter

IndexError: list index out of range
(12 additional frame(s) were not displayed)
...
  File "chronographer/event_handlers.py", line 112, in on_pr
    event.data['check_run']['check_suite']['pull_requests'][0]

[webknjaz]

This is kinda known: https://github.com/sanitizers/chronographer-github-app#known-issueslimitations. Perhaps we should log a warning and bail for now. Alternatively, we could try tracking the previous events and map this to PRs somehow...