Update OnCall Insights dashboard (#3875)

# What this PR does
- Remove panels with absolute alert groups count
- Update queries
- Replace "Team" and "Notifications" panels
## Which issue(s) this PR fixes
https://github.com/grafana/oncall/issues/3763
## Checklist

- [ ] Unit, integration, and e2e (if applicable) tests updated
- [x] Documentation added (or `pr:no public docs` PR label added if not
required)
- [x] `CHANGELOG.md` updated (or `pr:no changelog` PR label added if not
required)

CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Check for permissions on Slack escalate command ([#3891](https://github.com/grafana/oncall/pull/3891))
+- Update OnCall Insights dashboard @Ferril ([#3875](https://github.com/grafana/oncall/pull/3875))
 - Do not delete webhook if its team is deleted @mderynck ([#3873](https://github.com/grafana/oncall/pull/3873))
 
 ## v1.3.105 (2024-02-13)