MM-62782: Bumping minimum Postgres version to 13 (#30039)

As discussed in https://docs.mattermost.com/install/prepare-mattermost-database.html#minimum-supported-version-policy

https://mattermost.atlassian.net/browse/MM-62782

```release-note
Minimum postgres version has been bumped to 13.
```

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

server/channels/store/sqlstore/store.go

@@ -54,7 +54,7 @@ const (
 	// After 10, it's major and minor only.
 	// 10.1 would be 100001.
 	// 9.6.3 would be 90603.
-	minimumRequiredPostgresVersion = 110000
+	minimumRequiredPostgresVersion = 130000
 	// major*1000 + minor*100 + patch
 	minimumRequiredMySQLVersion = 8000