Alerting: Update grafana/alerting to 4f09f51

[grobinson-grafana]

What is this feature?

This pull request updates grafana/alerting to 4f09f51 to fix prometheus/alertmanager#3278.

Why do we need this feature?

[Add a description of the problem the feature is trying to solve.]

Who is this feature for?

[Add information on what kind of user the feature is for.]

Which issue(s) does this PR fix?:

Fixes #

Special notes for your reviewer:

Please check that:

• It works as expected from a user's perspective.
• If this is a pre-GA feature, it is behind a feature toggle.
• The docs are updated, and if this is a notable improvement, it's added to our What's New doc.

[JacobsonMT]

Should we go straight to grafana/alerting@5828396?

[gotjosh]

I can just make a second PR.

Agree with Matt here, not sure I see a reason for a second PR when grafana/alerting@5828396 is fairly trivial.

[grobinson-grafana]

Perhaps I didn't explain the reasoning well the first time around 🙁

The reason I wanted to create two separate PRs is so we can have a 1:1 relationship between the issue and the fix.

issue1 -> fix1
issue2 -> fix2

If we do both in the same PR we have this:

issue1 -> fix1and2
issue2 -> fix1and2

I wanted to have the former so if or when we go back and look at the issues it's super clear to see which PRs fixed it, rather than having a shared PR that fixes a number of different bugs all at the same time.

[grobinson-grafana]

Thanks! I had to rebase main to fix a conflict in go.sum.