Problem/Motivation
Currently in core we have no way to deprecate libraries included in core library files. As jQuery UI is EOL, we need a way to mark the various jQuery libraries as deprecated to be removed in Drupal 9 or 10.
Proposed resolution
From @catch:
For libraries the obvious place to trigger a deprecation error would be Drupal\Core\Asset\LibraryDiscovery::getLibraryByName() - by adding a 'deprecated' key to library definitions with a deprecation message as the value.
Remaining tasks
- RTBC
- Commit
- Publish change record
User interface changes
None
API changes
*.libraries.yml files will allow a new deprecation-message key which, if provided will trigger an error in Drupal\Core\Asset\LibraryDiscovery::getLibraryByName().
Data model changes
None
Release notes snippet
.libraries.yml files now support marking libraries as deprecated.
