[Bug]: Specify min pydantic and intake-esm versions in conda-forge recipe

[dougiesquire]

I'm not sure whether this issue should be opened here or in the ecgtools-feedstock repo.

The most recent release of ecgtools only works with pydantic >=2.0 and intake-esm >=2023.7.7. Should these be specified in the ecgtools feedstock recipes/metadata.yaml?

I tried to get these added in #166, but it was missed.