Prevent `Sqlg` upgrade code from down-grading the db version

[pietermartin]

When starting up an older version of the graph, its reported that it down-grades the db version.
This then in turn causes the previous later version to fail on start up.
In particular this happens from the 2.x to 3.x versions

[pietermartin]

@gustavo-armenta Both 2.1.8-SNAPSHOT and 3.1.6-SNAPSHOT has the the code change to not downgrade the graph version. It will log a warning when this scenario occurs.

[gustavo-armenta]

I tested the change and it works ok.
I renamed "2.1.8-SNAPSHOT" to "2.1.7" and "3.1.6-SNAPSHOT" to "3.1.3" so I could overwrite the jar files in the war file

Output of new 2.1.7 instances

2026-01-23 17:45:40.510 +0000 (,,,,) main : DEBUG org.umlg.sqlg.structure.SqlgStartupManager - SchemaManager.loadSqlgSchema()...
2026-01-23 17:45:40.527 +0000 (,,,,) main : DEBUG org.umlg.sqlg.structure.SqlgStartupManager - Time to createVertexLabel sqlg topology: 00:00:00.003
2026-01-23 17:45:40.639 +0000 (,,,,) main : WARN  org.umlg.sqlg.structure.topology.TopologyManager - An older version '2.1.7' of Sqlg is starting up on a graph with version '3.1.3'
This has undetermined behavior.
UPGRADE all Sqlg instances to be on the same version!!!
2026-01-23 17:45:40.639 +0000 (,,,,) main : DEBUG org.umlg.sqlg.structure.SqlgStartupManager - loadSqlgSchema() version=2.1.7, oldVersion=3.1.3, versionAsInt=313
2026-01-23 17:45:40.639 +0000 (,,,,) main : DEBUG org.umlg.sqlg.structure.SqlgStartupManager - updateTopology() v=3.1.3

Output of new 3.1.3 instances

2026-01-23 17:49:23.754 +0000 (,,,,) main : DEBUG org.umlg.sqlg.structure.SqlgStartupManager - SchemaManager.loadSqlgSchema()...
2026-01-23 17:49:23.772 +0000 (,,,,) main : DEBUG org.umlg.sqlg.structure.SqlgStartupManager - Time to createVertexLabel sqlg topology: 00:00:00.004
2026-01-23 17:49:23.908 +0000 (,,,,) main : DEBUG org.umlg.sqlg.structure.SqlgStartupManager - loadSqlgSchema() version=3.1.3, oldVersion=3.1.3, versionAsInt=313
2026-01-23 17:49:23.908 +0000 (,,,,) main : DEBUG org.umlg.sqlg.structure.topology.Topology - start cacheTopology

[pietermartin]

Great, I'll release 2.18
@gustavo-armenta What about #540 ? Is this still happening in your environment on 3.1.6?

[pietermartin]

@gustavo-armenta 2.1.8 has been released.