CI: group renovate update PRs

[florianl]

Instead of opening a PR for every dependency (like #476, #477, #478 and others), group dependency update PRs from renovate by their type.

[christos68k]

Can we also enable automerge? All PRs require 2 approvals (so there's no danger of reviews being missed) and it'll take away some of the tedium.

[florianl]

Can we also enable automerge?

Setting automerge in the repository settings, as directed in https://docs.renovatebot.com/key-concepts/automerge/#if-you-use-github-actions, is something I'm missing permission to do.

[christos68k]

Can we also enable automerge?

Setting automerge in the repository settings, as directed in https://docs.renovatebot.com/key-concepts/automerge/#if-you-use-github-actions, is something I'm missing permission to do.

Auto-merge is already set in the repository settings (also the section you linked to is specific to enabling the merge queue which isn't a requirement for automerge). So unless I'm missing something, all we need to do is add "automerge": true to the relevant sections of the renovate.json5 file.