mattermost update to 11.0.4-bb.0

Package Merge Request

Package Changes

https://repo1.dso.mil/big-bang/product/packages/mattermost/-/blob/11.0.4-bb.0/CHANGELOG.md

Package MR

big-bang/product/packages/mattermost!335 (merged)

For Issue

Closes big-bang/product/packages/mattermost#234 (closed) issue

Upgrade Notices

The internal PostgreSQL has been updated to release 18 which requires a dump/restore using pg_dumpall or using pg_upgrade for migrating data to this new, major release. Platform One does not support an internal postgres database for production deployments. This option should only be used for development or CI pipelines. Documentation and other changes can be found here: https://www.postgresql.org/docs/18/release-18.html#RELEASE-18-MIGRATION