[Transform] Remove wire serialization version checks for <7.17

[hendrikmuhs]

a lot of version classes still do wire serialization version checks. For actions BWC layers have been removed in #79927, but the configuration classes (TransformConfig) still have version checks in writeTo and the corresponding readers.

Best if this get addressed after 7.17 has been branched, so the latest addition #81491 can be removed, too.

[elasticmachine]

Pinging @elastic/ml-core (Team:ML)

[hendrikmuhs]

fixed by #91150