Webform text format appear in the list of allowed formats in field config

Problem/Motivation

The disabled webform text format appears in the allowed list in field config, even though it's disabled. If you select it, it doesn't work.

Disabled format:

Field config:

Empty options:

Steps to reproduce

1. Edit an existing formatted text field
2. See the disabled format is listed
3. Select it as the only allowed format
4. Edit a node of this type and see there is no format selected

Proposed resolution

This format should not appear here since it shouldn't be used.

Remaining tasks

1. Create MR for fix
2. Add tests
3. Review
4. Commit

User interface changes

As above.

Introduced terminology

N/A

API changes

N/A

Data model changes

N/A

Release notes snippet

N/A