Describe the bug
When using the "bulk actions" tool in proposals currently (and in budget projects after #8986), the admin cannot select the top category from the re-categorization list in case the category has sub-categories.

To Reproduce
Steps to reproduce the behavior:

1. Go to participatory space admin
2. Make sure the participatory space has categories and at least one category with sub-categories in it
3. Go to the proposals component
4. Select multiple proposals
5. Using the bulk-actions, categorize the proposals to one of the sub-categories
6. Once updated, try to re-categorize the same proposals to the top category (which has sub-categories)
7. Notice you cannot select the top category from the list

Expected behavior
I would expect to be able to select also the top category from the list. This is especially confusing when the proposal previously was categorized in the top-category, you accidentally change it to one of the sub-categories and after that you can no longer fix your mistake.

Screenshots

Stacktrace
N/A

Extra data (please complete the following information):

• Device: (any)
• Device OS: (any)
• Browser: (any)
• Decidim Version: develop
• Decidim installation: (any)

Additional context
This issue was noticed when reviewing #8986.