[meta] Remove deprecated classes, methods, procedural functions and code paths outside of deprecated extensions from Drupal 13

Problem/Motivation

The deprecated code scheduled for removal in Drupal 13 should be removed. This issue is for classes, methods, procedural functions and code paths that are not in wholly deprecated extensions.

Deprecated extensions are managed in their own meta issue.

Proposed resolution

1. Check with subsystem and topic maintainers to determine what, if any, removals they wish to do themselve.
2. Removals must be scoped sensibly. It is an evolving process that improves with each major release.
3. All removal issues should be a child of this issue.
4. Do not make issues per file.

core/lib directory

We are currently testing removing code from directories alphabetically with a maximum of about 15 deprecations per issue.

Extensions

> For modules I want to try the same strategy but also by modules that make sense together. Example workspaces + workspaces Ui.

1. Do not remove deprecated extensions in this issue.
2. In general, group work by modules that are related. One example is workspaces + workspaces Ui

Remaining tasks

Add here removal or others tasks that there is not yet a child issue for.

• TBA