MM-53688 Remove boards dataretention (#24231)

* remove boards data-retention

* remove another variable

* update snapshots, to remove boards

* need to keep config settings until focalboard is updated

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

server/public/model/feature_flags.go

@@ -27,9 +27,6 @@ type FeatureFlags struct {
 	// CallsEnabled controls whether or not the Calls plugin should be enabled
 	CallsEnabled bool
 
-	// Enable DataRetention for Boards
-	BoardsDataRetention bool
-
 	NormalizeLdapDNs bool
 
 	// Enable GraphQL feature
@@ -58,7 +55,6 @@ func (f *FeatureFlags) SetDefaults() {
 	f.TestBoolFeature = false
 	f.EnableRemoteClusterService = false
 	f.AppsEnabled = true
-	f.BoardsDataRetention = false
 	f.NormalizeLdapDNs = false
 	f.GraphQL = false
 	f.CallsEnabled = true