Auth: Only call rotate token if we have a session expiry cookie

[kalleep]

What is this feature?
When getting a 401 response we always tried to rotate token. This works correctly as long as a user has a sessions cookie. But there are cases when a user don't have one (anonymous and auth proxy). When the server respond with a 401 this is causing a infinite reload loop for that page.

To solve this we only call rotate token if we have a session expiry cookie and in all other cases we call GET /api/login/ping to determine if user is authenticated.

For 10.3.x and below this can be mitigated by disabling the feature toggle. But in 10.4.x the toggle is removed and this is the default behaviour.

Why do we need this feature?
To solve issue with infinite page reload loop for users without a sessions.

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.

[grafana-delivery-bot]

This PR must be merged before a backport PR will be created.

[grafana-delivery-bot]

This PR must be merged before a backport PR will be created.

[grafana-delivery-bot]

This PR must be merged before a backport PR will be created.

[grafana-delivery-bot]

The backport to v10.3.x 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-84169-to-v10.3.x origin/v10.3.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x 4272483c54a55d807788c163963b70071343eba4

When the conflicts are resolved, stage and commit the changes:

git add . && git cherry-pick --continue

If you have the GitHub CLI installed:

# Push the branch to GitHub:
git push --set-upstream origin backport-84169-to-v10.3.x
# Create the PR body template
PR_BODY=$(gh pr view 84169 --json body --template 'Backport 4272483c54a55d807788c163963b70071343eba4 from #84169{{ "\n\n---\n\n" }}{{ index . "body" }}')
# Create the PR on GitHub
echo "${PR_BODY}" | gh pr create --title "[v10.3.x] Auth: Only call rotate token if we have a session expiry cookie" --body-file - --label "type/bug" --label "area/frontend" --label "add to changelog" --label "backport" --base v10.3.x --milestone 10.3.x --web

Or, if you don't have the GitHub CLI installed (we recommend you install it!):

# Push the branch to GitHub:
git push --set-upstream origin backport-84169-to-v10.3.x

# Create a pull request where the `base` branch is `v10.3.x` and the `compare`/`head` branch is `backport-84169-to-v10.3.x`.

# Remove the local backport branch
git switch main
git branch -D backport-84169-to-v10.3.x