Remove the Farbtastic color selector plugin

Problem/Motivation

From 4.0.0 release notes (Dec 10, 2024):

Known issues

• The Color backport → module does not have a Drupal 11 compatible release yet. If you are using the Farbtastic plugin for color selection, the 2.x-dev branch was tested and seems to work fine. If no Drupal 11 compatible release comes earlier, the Farbtastic plugin will be removed in next minor of Image Effects.

There has been no progress since then.

Proposed resolution

Remove the 'Farbtastic' plugin.

Remaining tasks

User interface changes

API changes

Data model changes