github_checks.annotations should default to False

[jakkdl]

For quite a while I and various other co-developers have repeatedly been misled by stale annotations (e.g. https://github.com/pytest-dev/pytest/pull/13016/files#r1868983441), and once I finally decide to dig into it I found the big red box on https://docs.codecov.com/docs/github-checks warning that annotations are unreliable and deprecated.

In my opinion that makes the costs of the feature vastly higher than the benefits, and given that it's deprecated you don't seem to disagree, but I'm then very surprised to see that it's still enabled by default! I will now have to go through all repositories/orgs and manually disable it - but unless I've misunderstood the state of things I very much think it should be default-disabled (or feature a big warning somewhere) as it repeatedly wastes developer time from the confusion.