promtail update to 6.16.6-bb.4

Package Merge Request

Package Changes

https://repo1.dso.mil/big-bang/product/packages/promtail/-/blob/6.16.6-bb.4/CHANGELOG.md

Package MR

big-bang/product/packages/promtail!117

For Issue

Closes big-bang/product/packages/promtail#82

Upgrade Notices

N/A