[FIX] Grant maintainer privileges to superuser and fix attention set handling

[DATVenancio]

Description

This PR grants maintainer privileges to superusers to ensure consistency with other PRs. It also fixes two bugs: the 'Review Interest' column in the patch list template was showing all users who had been added to the attention set, even if they were later removed; and the patch details view would cause an error if a user who was removed from the attention set tried to declare interest again. Additionally, it fixes problems in the partial update implementation used to change the attention set, which was not checking if a non-maintainer user was changing only the attention set field, causing the tests to break.

Progress

• Grant maintainer privileges to superusers in the API.
• Grant maintainer privileges to superusers in the view.
• Fix bug where excluded users were still shown in the patch list template.
• Fix bug preventing a removed user from declaring interest again in the patch details view.
• Fix partial update implementation to check if a non-maintainer user is changing only the attention set.

Pull request checklist

• Tests: This PR includes tests for covering the features or bug fixes (if applicable).
• Docs: This PR updates/creates the necessary documentation.
• CI: Make sure your Pull Request passes all CI checks. If not, clarify the motif behind that and the action plan to solve it (may reference a ticket)

How to test it

Log in as a normal user and declare interest in a patch. Log in as a different user with superuser status and navigate to the patch details page. Remove the first user's interest in the patch, check it works. Repeat the process using the API. Once the user's interest has been removed, log back in as the normal user and try to declare interest in the same patch again, check it works.