Currently, ./xmodule/ unit tests are only run with LMS settings. However,
./common/ and ./xmodule/ are run twice: once with LMS settings and once with
CMS settings.
Just like ./common/ and ./openedx/, the unit tests in ./xmodule/ validate
behavior in both LMS and CMS. So, order to fully test ./xmodule/, we should to
run its tests with CMS settings too.
This will enable us to better validate certain LibraryContentBlocks behaviors
being touched by https://github.com/openedx/edx-platform/pull/33263 which can't
be expressed under LMS settings.
Also in this commit:
* refactor: rename the shards to be clear whether they're running under LMS or CMS
* docs: correct comments regarding conditions under which codejail's
test_cant_do_something_forbidden is skipped.
* test: update a unit test which was using the now-deleted library_sourced block to use
library_content block instead.
9c6e765bf6