Remove cli module

[edeno]

Description

The cli module is only used by a small subset of users and unmaintained. I propose we remove it.

Checklist:

• This PR should be accompanied by a release: (yes/no/unsure)
• If release, I have updated the CITATION.cff
• This PR makes edits to table definitions: (yes/no)
• If table edits, I have included an alter snippet for release notes.
• If this PR makes changes to position, I ran the relevant tests locally.
• I have updated the CHANGELOG.md with PR number and description.
• I have added/edited docs/notebooks to reflect the changes

[CBroz1]

1. I would remove this line
2. Is there any argument for taking the time to declare a new spyglass_cli installable package? Or do we think it's the case that no one uses this?

[edeno]

I think @magland might possibly be the only person using it. It would be simple enough to make it a separate package.

[magland]

I think @magland might possibly be the only person using it. It would be simple enough to make it a separate package.

not using it