Latest 1.1.0a1 pre-release is incomplete

[gouttegd]

All the schema-derived files have not been generated prior to making the 1.1.0a1 pre-release, therefore that release provides files that do not contain the latest change from the schema.

Notably, the sssom_schema.py module, which contains the Python classes and enums derived from the model, was last updated in #409, 6 months ago.

We must generate all derived files (by running make all, which in turns calls LinkML’s gen-project), commit all the newly updated files, and then make a real 1.1.0a2 release.