This PR is similar to PR #7712

The Categories list view has two ordering options:
1. You can order the list of Article or Featured Article items on any column by clicking on the column heading (Status, Title, Access, Author, Language, Date, Hits, ID). You can reverse the order direction by clicking a second time on the same column heading.
2. Another way to order the list is to click the Sort Table By: dropdown option. However that name is never visible there. The list is already ordered by default and the default ordering option is: "Ordering ascending".

IMHO option 2 Sort Table By: dropdown option is not very user friendly for new users. The "Ordering ascending" option is confusing. And for experienced users it's another option to focus on. And because all ordering options are already available via column headers (option 1), I decided to create this PR to remove the duplicate ordering dropdown option

Testing instructions

Before the PR

Content > Categories

The list of Articles can be ordered by clicking on column headers,
and by clicking on the "Sort Table By" dropdown option on the top right.

After the PR

Content > Categories

The list of Articles can be ordered by clicking on column headers. The duplicate "Sort Table By" dropdown has been removed and the user has one option less too focus on.

Note that com_categories is used by other components!

Banners, Contacts, Newsfeeds (and the removed component Weblinks) all use com_categories to manage the categories for their items. After installing this PR the duplicate option should be removed for those components as well.
For example the Category view of the Banners Component:

Components > Banners > Categories

Before PR

After PR