global config: make all event dataset definitions depend on both datacenters

In T338796, we made all event sensors depend on both datacenters, but then, we reverted it (via !614 (merged)) since it was unreliable as canary events were having all sorts of issues at that moment. We then forgot about it. But this issue affects most all of our event stream sensors; we are only depending on codfw while eqiad is the main datacenter, so this issue has been affecting us since at least the last datacenter switchover (and these happen twice a year at equinox, so since March 20 2025.).

We now have a more robust canary system, so I will now apply the changes from T338796 again, which means all event sensors will depend on both datacenters.

More info at https://phabricator.wikimedia.org/T397525#10948123

Bug: T338796

Bug: T397525