grafana update to 8.6.0-bb.0, loki update to 6.18.0-bb.3

Package Merge Request

Package Changes

https://repo1.dso.mil/big-bang/product/packages/grafana/-/blob/8.6.0-bb.0/CHANGELOG.md https://repo1.dso.mil/big-bang/product/packages/loki/-/blob/6.18.0-bb.3/CHANGELOG.md

Package MR

big-bang/product/packages/grafana!168 (merged) big-bang/product/packages/loki!290 (merged)

For Issue

Closes big-bang/product/packages/grafana#121

Upgrade Notices

N/A