chore(schemas): update to pydantic v2

[mikewilli]

Because

• the schemas package is used by a lot of data tooling
• the data tooling is starting to complain about schemas requiring pydantic v1 due to other dependencies
• the pydantic-to-typescript package is outdated and does not support pydantic v2

This commit

• updates the schemas package to v2
• changes the typescript generation to a script internal to experimenter

Fixes #11214