fix: unbreak docker-compose.yml

[johanandren]

Something wrong with some brackets there (not sure why they are in there to start with though)

[efgpinto]

Feels like a copy-pasta-gone-wrong from previous commit copied from the maven archetype one, where we use those weird things to be able to declare a container_name with a artifatId, see here.

So I think we could remove those here. (we could also probably add the container name here, not sure what the syntax looks like in g8).

[johanandren]

Removed. Note that there is templating/substitution for g8 templates as well, with a dont-substitute-list in default.properties, I wonder if that is needed here to to not replace the envs https://github.com/akka/akka-grpc-quickstart-scala.g8/blob/main/src/main/g8/default.properties#L8C1-L8C10

[johanandren]

Created a new project and verified nothing funky ends up happening to the docker-compose.yml