Bump version to 4.6.3

v4.6.1 - Python event_data fixes + python 3.13 and 3.14 pre-builds

Plug a memory leak

Merge branch 'concurrent_crashes' into 'main'

Problem: Unlocking the model mutex to call the callbacks means that our context may have changed when the callback returns and the lock is acquired again.

See merge request ingescape-private/ingescape-library!15