chore(tooling): explore extended `pydantic.mypy` plugin options

We could explore the options for the `pydantic.mypy` plugin to make our typechecking stricter, see the list [here](https://docs.pydantic.dev/latest/integrations/mypy/#configuring-the-plugin).

Note: `mypy` was updated to `1.15` in #1209; the `pydantic.mypy` plugin may not be fully tested with this newer release.