MM-15064: allow running with future minor db versions (#10636)

* MM-15064: allow running with future minor db versions

This is to support running another community cluster that stays on the most recent stable version while we test upcoming versions.

During the past few releases, we have committed to not making backwards incompatible schema changes across minor versions. This means that a 5.x server can run against any 5.y schema, y >= x. (It will upgrade to x if y < x).

* check errors on incoming versions vs. Must/panic

* fix TestSaveSchemaVersion

store/sqlstore/supplier.go

@@ -164,7 +164,12 @@ func NewSqlSupplier(settings model.SqlSettings, metrics einterfaces.MetricsInter
 		os.Exit(EXIT_CREATE_TABLE)
 	}
 
-	UpgradeDatabase(supplier)
+	err = UpgradeDatabase(supplier, model.CurrentVersion)
+	if err != nil {
+		mlog.Critical("Failed to upgrade database", mlog.Err(err))
+		time.Sleep(time.Second)
+		os.Exit(EXIT_GENERIC_FAILURE)
+	}
 
 	supplier.oldStores.team.(*SqlTeamStore).CreateIndexesIfNotExists()
 	supplier.oldStores.channel.(*SqlChannelStore).CreateIndexesIfNotExists()