Remove the devise-specific fields from spree_users

[elia]

Let solidus_auth_devise add and maintain the fields it needs.

Extracted from #3923

Description

Checklist:

• I have followed Pull Request guidelines
• I have added a detailed description into each commit message
• I have updated Guides and README accordingly to this change (if needed)
• I have added tests to cover this change (if needed)
• I have attached screenshots to this PR for visual changes (if needed)

[waiting-for-dev]

@elia, I think that if you rebase from master CI will be green 🪄

[waiting-for-dev]

Hey, @elia, is it ready for review? 🙂

[fthobe]

@elia did this ever make it over the finish line?

[elia]

@fthobe no, it needs those columns to be added individually in solidus_auth_devise first, not a difficult change if the CI is in good shape

[fthobe]

I saw only a migration failing, do you want to give it another try by re triggering?

You were quicker

[elia]

No, it wouldn't change a thing, we remove columns here where they don't belong, but it won't pass until auth devise adds support for them if they're missing.

[jarednorman]

Closing in favour of #6442. Additionally, the work is now tracked on the solidus_auth_devise repo here: solidusio/solidus_auth_devise#274.