Drop pydantic v1 compatibility#8

anoadragon453-codex wants to merge 1 commit intodevelopanoadragon453-codex/synapse:developfrom

codex/migrate-codebase-to-pydantic-v2-onlyanoadragon453-codex/synapse:codex/migrate-codebase-to-pydantic-v2-onlyCopy head branch name to clipboard