Update colos list

The colos list at https://github.com/cloudflare/cloudflare-gcp/blob/master/security-events/static/colos.json appears to be very outdated and could do with being updated.

Any chance we could get this updated please? 👀

Start by inspecting security-events/static/colos.json and the surrounding security-events files to understand how the list is used. The issue does not name an authoritative source or tests; done means updating the file with a current colos list and verifying its JSON remains valid.

Written by the indexing model from the issue text.