fix alloy-logs dashboard

[hervenicol]

This PR fixes the Alloy / Logs Overview dashboard:

• templates:

  • cluster_id instead of cluster
  • scrape_job instead of job

• queries:

  • use proper label names
  • remove unexpected comma

• screenshots before:
  

• screenshots after:
  

Checklist

• Update changelog in CHANGELOG.md in an end-user friendly language.

[QuentinBisson]

Did you fix it using the mixsin script?

[TheoBrigitte]

Suggested change

	- fix Alloy / Logs Overview dashboard.
	### Fixed
	- Fix Alloy / Logs Overview dashboard.

[hervenicol]

Did you fix it using the mixsin script?

Nope. Will look at the script and try to do it this way then.

[hervenicol]

After looking at the upstream mixins and pulling my (few remaining) hair at the dependencies maze that it is, I decided to just do a bit of sed magic.

I can't guarantee that alloy dashboards are all bug-free, but they certainly work better after these changes than before.