chore: Configure renovate to be more in line to the end state

What this PR does / why we need it:

This PR attempts to align the renovate configuration to our end goal, with respect to the main branch. Notably it:

Separates out Helm updates, so they are not mixed with Dockerfile updates
Explicitly sets Helm updates to not be automerged, since they require documentation updates
Separates out lambda-promtail updates so they are not merged with other Go updates, since they require Nix updates
Explicity sets the lamba-promtail updates to not be automerged
Disables Renovate updates for the Operator code
Explicitly sets GitHub actions to not be automerged
Converts the configuration to JSON5, so that each rule can be annotated and explained

Which issue(s) this PR fixes: Fixes #

Special notes for your reviewer:

Checklist

[X] Reviewed the CONTRIBUTING.md guide (required)
[ ] Documentation added
[ ] Tests updated
[X] Title matches the required conventional commits format, see here
- Note that Promtail is considered to be feature complete, and future development for logs collection will be in Grafana Alloy. As such, feat PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
[ ] Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
[ ] If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR

grafana / loki