mattermost update to 10.9.1-bb.2

Package Merge Request

Package Changes

https://repo1.dso.mil/big-bang/product/packages/mattermost/-/blob/10.9.1-bb.2/CHANGELOG.md

Package MR

big-bang/product/packages/mattermost!320 (merged)

For Issue

Closes Renovate: Upgrade Mattermost Package Dependencies (#220) · Issue · big-bang/product/packages/mattermost

Upgrade Notices

N/A