Merge branch 'update-mattermost-tag-9.3.0-bb.1' into 'master'

mattermost update to 9.3.0-bb.1

Closes big-bang/product/packages/mattermost#96

See merge request !3662

chart/values.yaml

@@ -1623,11 +1623,11 @@ addons:
     git:
       repo: https://repo1.dso.mil/big-bang/product/packages/mattermost.git
       path: "./chart"
-      tag: "v9.2.3-bb.2"
+      tag: "9.3.0-bb.1"
     helmRepo:
       repoName: "registry1"
       chartName: "mattermost"
-      tag: "v9.2.3-bb.2"
+      tag: "9.3.0-bb.1"
 
     # -- Flux reconciliation overrides specifically for the Mattermost Package
     flux: {}