Drop MySQL 5.7 support

[silverwind]

MySQL 5.7 will reach EOL in 4 months. We should:

• Drop it from CI matrix and remove relevant Makefile targets
• Update docs that MySQL 8.0 or greater is required

[lunny]

We can do it step by step. Firstly prevent new installation to chose mysql 5.7 but that askes Gitea read versions from database.

[silverwind]

I'm primarily looking to remove it from CI. We don't need to deliberatily go out of the way to break it for users unless there are valid reasons to do so.

[lunny]

Maybe we can have an announcement for that first and maybe 1.22 is a better version to remove mysql5.7 CI and new installation?

[silverwind]

Sounds ok. We should remove it from CI after 1.22 branch is created. Don't think it needs any big announcement, just update requirements in the docs.

[yakob-aleksandrovich]

Is there already a roadmap for when support for MySQL 5.7 will be fully dropped? Which branch would that be?
This would help me and various others in planning for an upgrade of our infrastructure.

[delvh]

…

main, since the instant we forked the release/v1.21 branch.

So far, we haven't dropped MySQL 5.7 support.
If it happens, it will probably happen around or after the release of 1.21.0, but not before.

[silverwind]

Will likely happen in 1.22.

[delvh]

Yes, but the question was when exactly is 'in 1.22'.
The range ranges from now to feature freeze in three months…

[silverwind]

It shouldn't really matter. It will be a sort of soft-deprecation of support anyways, e.g. in theory 5.7 will still work in 1.22, we just don't actively test it anymore, and will start testing 8.0 and likely 8.1 instead.