Helm / Jsonnet: align terminationGracePeriodSeconds

[pracucci]

What this PR does

Jsonnet and Helm terminationGracePeriodSeconds are unaligned. In this PR I'm proposing to align them, so that assert on differences between the two and easily spot when they diverge.

Which values did I pick?

• For most components, I took Jsonnet as leader (as usual)
• Querier and query-scheduler terminationGracePeriodSeconds was set to 30 in Jsonnet. I think that's not right. We should have a terminationGracePeriodSeconds higher than query timeout (2m by default) so in this PR I propose to pick Helm as leader.

Which issue(s) this PR fixes or relates to

N/A

Checklist

• [ ] Tests updated.
• [ ] Documentation added.
• [x] CHANGELOG.md updated - the order of entries should be [CHANGE], [FEATURE], [ENHANCEMENT], [BUGFIX].
• [ ] about-versioning.md updated with experimental features.

[pracucci]

Switched to draft because I want to roll it out at Grafana Labs first.

[duricanikolic]

The CHANGELOG has just been cut to prepare for the next Mimir release. Please rebase main and eventually move the CHANGELOG entry added / updated in this PR to the top of the CHANGELOG document. Thanks!

[pracucci]

I rebased the PR and double checked it to ensure the changes have not changed (no pun intended).