[WIP] add EIA860M May 2025

[marianneke]

Overview

Closes #4379.

What problem does this address?

What did you change?

Documentation

Make sure to update relevant aspects of the documentation:

• Update the release notes: reference the PR and related issues.
• Update relevant Data Source jinja templates (see docs/data_sources/templates).
• Update relevant table or source description metadata (see src/metadata).
• Review and update any other aspects of the documentation that might be affected by this PR.

Testing

How did you make sure this worked? How can a reviewer verify this?

To-do list

• If updating analyses or data processing functions: make sure to update row count expectations in dbt tests.
• Run make pytest-coverage locally to ensure that the merge queue will accept your PR.
• Review the PR yourself and call out any questions or issues you have.
• 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.
• For bigger ETL or data changes run the full ETL locally and then run the data validations using make pytest-validate.
• Alternatively, run the build-deploy-pudl GitHub Action manually.