Fix accidental copy change causing dangling migration

[sarayourfriend]

Fixes

Related to #3310 by @sarayourfriend (leaving the issue open to investigate why the check action didn't catch this)

Description

In #3022 we updated the abstract mature media model's help text, and that PR already included a migration to change the help text on the MatureImage model. However, we accidentally missed the model-code side change of that, and the model still had the old copy defined. This was causing a migration to revert the help text back to the term "mature". Changing the help text to match the previous migration introduced in the referenced PR, removes the dangling migration.

This PR doesn't result in any migrations, therefore, so there's no care needed for deployment.

Testing Instructions

Run just api/dj makemigrations and confirm the dangling migration that appears on main no longer exists.

Checklist

• My pull request has a descriptive title (not a vague title likeUpdate index.md).
• My pull request targets the default branch of the repository (main) or a parent feature branch.
• My commit messages follow best practices.
• My code follows the established code style of the repository.
• [N/A] I added or updated tests for the changes I made (if applicable).
• [N/A] I added or updated documentation (if applicable).
• I tried running the project locally and verified that there are no visible errors.
• [N/A] I ran the DAG documentation generator (if applicable).

Developer Certificate of Origin

Developer Certificate of Origin

Developer Certificate of Origin
Version 1.1

Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
1 Letterman Drive
Suite D4700
San Francisco, CA, 94129

Everyone is permitted to copy and distribute verbatim copies of this
license document, but changing it is not allowed.


Developer's Certificate of Origin 1.1

By making a contribution to this project, I certify that:

(a) The contribution was created in whole or in part by me and I
    have the right to submit it under the open source license
    indicated in the file; or

(b) The contribution is based upon previous work that, to the best
    of my knowledge, is covered under an appropriate open source
    license and I have the right under that license to submit that
    work with modifications, whether created in whole or in part
    by me, under the same open source license (unless I am
    permitted to submit under a different license), as indicated
    in the file; or

(c) The contribution was provided directly to me by some other
    person who certified (a), (b) or (c) and I have not modified
    it.

(d) I understand and agree that this project and the contribution
    are public and that a record of the contribution (including all
    personal information I submit with it, including my sign-off) is
    maintained indefinitely and may be redistributed consistent with
    this project or the open source license(s) involved.