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

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

webapp/platform/types/src/config.ts

@@ -790,10 +790,8 @@ export type BleveSettings = {
 export type DataRetentionSettings = {
     EnableMessageDeletion: boolean;
     EnableFileDeletion: boolean;
-    EnableBoardsDeletion: boolean;
     MessageRetentionDays: number;
     FileRetentionDays: number;
-    BoardsRetentionDays: number;
     DeletionJobStartTime: string;
     BatchSize: number;
 };