CI: Ensure all minimum optional dependencies are tested
- [x] tests added / passed

Progress towards https://github.com/pandas-dev/pandas/issues/29685

- `actions-38-minimum_versions.yaml` now contains all optional dependencies with their min versions
    - Other builds that have min version pinned are now removed
- `actions-38-db.yaml` -> `actions-38-downstream_compat.yaml`
    - Build for compat with libraries like statsmodels, pytorch, yaml, etc
- `actions-38-db-min.yaml` removed as redundant with `actions-38-minimum_versions.yaml`

Discoveries:
Min version of lxml and openpyxl with `.xlsm` or `.xlsx` doesn't seem to work. Need to bump to openpyxl to 3.0.9 https://openpyxl.readthedocs.io/en/stable/changes.html#id47
@mroeschke 

>  Need to bump to openpyxl to 3.0.9

you updated the dev deps for this?

cc @lithomas1 can you review > you updated the dev deps for this?

Don't think so. lxml and openpyxl don't have pins in `environment.yml` and `requirements-dev.txt` so the more recent versions should be installed. thanks @mroeschke @lithomas1 