MM-27187: Use the correct page offset for cache clear methods (#15094)

* MM-27187: Use the correct page offset for cache clear methods

We were just using page and incrementing by 1. This would fetch pages
one by one like (1-100, 2-102, 3-103) rather than (1-100,100-200,200-300).

We fix that to update the correct page offset.

* Trigger CI

app/channel.go

@@ -2589,7 +2589,7 @@ func (a *App) ClearChannelMembersCache(channelID string) {
 	page := 0
 
 	for {
-		channelMembers, err := a.Srv().Store.Channel().GetMembers(channelID, page, perPage)
+		channelMembers, err := a.Srv().Store.Channel().GetMembers(channelID, page*perPage, perPage)
 		if err != nil {
 			a.Log().Warn("error clearing cache for channel members", mlog.String("channel_id", channelID))
 			break