Partial revert of #12369 for celery visibility timeout (#12442)
We are noticing all builds restarting at 17.25m (15m * 115%), reverting
this back to 5hours for now. In theory, tasks are being executed with
ack_late=False so they should immediately acknowledge the task and avoid
the visibility timeout entirely. But in practice this doesn't seem to
happen and the build task acts like ack_late=True with a 17.25min
visibility timeout, duplicating the build task on another builder.
- Related https://github.com/readthedocs/readthedocs.org/pull/12369
- We discussed the potential for low timeout bugs at
https://github.com/readthedocs/readthedocs.org/pull/12393
- This bug is identical to
https://github.com/readthedocs/readthedocs.org/issues/12317 except the
timeout is 17m now instead of 1h