Switch to docker-compose stop for stopping containers

I do not understand the reason why we should use "rm" instead of "stop".

This fixes podman compatibility:
https://discuss.overhang.io/t/tutor-with-podman-not-working/905

CHANGELOG.md

@@ -4,6 +4,7 @@ Note: Breaking changes between versions are indicated by "💥".
 
 ## Unreleased
 
+- [Bugfix] Fix podman compatibility by replacing `docker-compose rm` command by `docker-compose stop` when stopping containers
 - [Improvement] Improve plugin data deletion
 - [Improvement] Introduce the `OPENEDX_COMMON_VERSION` setting
 - [Bugfix] Make it possible to run init jobs without starting the entire platform

tutor/commands/compose.py

@@ -96,7 +96,7 @@ def start(context, detach, services):
 @click.pass_obj
 def stop(context, services):
     config = tutor_config.load(context.root)
-    context.docker_compose(context.root, config, "rm", "--stop", "--force", *services)
+    context.docker_compose(context.root, config, "stop", *services)
 
 
 @click.command(