Promote experimental features to stable

[dimitarvdimitrov]

What this PR does

• ruler tenant federation support
• limiting max-tenants for federated queries
• enabling/disabling recording & alerting rules per tenant

I looked mostly at features that have been added a long time ago (~2 years for ruler changes) and that have been at use extensively by the community (multi-tenant ruler) or at Grafana Labs (enabling/disabling rule evaluations & max-tenants limit for federated queries).

This PR also fixes a typo and adds the PR number for a changelog entry

Which issue(s) this PR fixes or relates to

Related to #8390

Checklist

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

[pracucci]

I checked all other experimental features listed at docs/sources/mimir/configure/about-versioning.md and I can't see anything that I'm very eager to promote to stable, so LGTM.

[56quarters]

LGTM.

While we're here, -tenant-federation.max-tenants is OK to be promoted to stable.

[grafanabot]

The backport to r295 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new branch
git switch --create backport-8400-to-r295 origin/r295
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x 69c0f88d9174465d690e10d92552a7d9afa3cac2
# Push it to GitHub
git push --set-upstream origin backport-8400-to-r295
git switch main
# Remove the local backport branch
git branch -D backport-8400-to-r295

Then, create a pull request where the base branch is r295 and the compare/head branch is backport-8400-to-r295.