feat: don't run Celery workers in dev mode

Tutor's importing * from devstack.py[1] for the development settings,
and that means that we aren't using Celery workers at all in dev mode
(see [2]).  This removes them from the dev compose file, thus saving
everyboding a significant chunk of RAM.

[1] https://github.com/overhangio/tutor/blob/master/tutor/templates/apps/openedx/settings/lms/development.py#L3
[2] https://github.com/openedx/edx-platform/blob/master/lms/envs/devstack.py#L35

changelog.d/20240416_162659_arbrandes_no_workers_in_dev.md

@@ -0,0 +1 @@
+- [Feature] Don't start Celery workers in dev mode, as they're never used. (by @arbrandes) -->

tutor/templates/dev/docker-compose.yml

@@ -34,12 +34,6 @@ services:
     ports:
         - "8001:8000"
 
-  lms-worker:
-    <<: *openedx-service
-
-  cms-worker:
-    <<: *openedx-service
-
   # Additional service for watching theme changes
   watchthemes:
     <<: *openedx-service