Add Q2 2024 CEMS data

[e-belfer]

Overview

Closes #3762.

What problem does this address?
Adds Q2 of CEMS data into PUDL.

What did you change?

• Updated the Zenodo DOI for datastore.
• Updated docs to remove reference to non-existent asset groups

Testing

How did you make sure this worked? How can a reviewer verify this?
Generated the CEMS assets and all downstream outputs. Double checked to make sure that no validation tests are impacted, and ran minmax row tests.

To-do list

Preview Give feedback

1. If updating analyses or data processing functions: make sure to update or write data validation tests (e.g. test_minmax_rows())
2. Update the release notes: reference the PR and related issues.
3. Review the PR yourself and call out any questions or issues you have
4. For minor ETL changes or data additions, once make pytest-coverage passes, make sure you have a fresh full PUDL DB downloaded locally, materialize new/changed assets and all their downstream assets and run relevant data validation tests using pytest and --live-dbs.

[aesharpe]

Looks pretty chill!

[aesharpe]

Good catch!