feat: add redis sentinel

[daddyy]

What this PR does

Which issue(s) this PR closes

Related to https://github.com/grafana/oncall/issues/2312 https://github.com/grafana/oncall/issues/4360

Checklist

• [ ] Unit, integration, and e2e (if applicable) tests updated
• [ ] Documentation added (or pr:no public docs PR label added if not required)
• [ ] Added the relevant release notes label (see labels prefixed w/ release:). These labels dictate how your PR will show up in the autogenerated release notes.

[CLAassistant]

All committers have signed the CLA.

[daddyy]

Sorry for the delay and for not marking it as a draft earlier. I believe the code is now ready for review.

[github-actions[bot]]

This pull request has been automatically marked as stale because it has not had activity in the last 30 days. It will be closed in 30 days if no further activity occurs. Please feel free to give a status update now, ping for review, or re-open when it's ready. Thank you for your contributions!

[github-actions[bot]]

This pull request has been automatically closed because it has not had activity in the last 30 days. Please feel free to give a status update now, ping for review, or re-open when it's ready. Thank you for your contributions!