What I did

1. Remove redundant len(v) > 0 checks in docker compose run command.

   From the Go specification (https://go.dev/ref/spec#For_range):

   "1. For a nil slice, the number of iterations is 0."

   len returns 0 if the slice is nil (https://pkg.go.dev/builtin#len). Therefore, checking len(v) > 0 before a loop is unnecessary.

   Also it is unnecessary to initialise target.Ports = []types.ServicePortConfig{}. append works on nil slices (https://go.dev/tour/moretypes/15).

2. Update existing test case for docker compose run --publish and add a new test case for docker compose run --service-ports to verify the documented behaviour.

   compose/docs/reference/compose_run.md

   Lines 52 to 64 in a345515

   	The second difference is that the `docker compose run` command does not create any of the ports specified in the
   	service configuration. This prevents port collisions with already-open ports. If you do want the service’s ports
   	to be created and mapped to the host, specify the `--service-ports`
   	```console
   	$ docker compose run --service-ports web python manage.py shell
   	```
   	Alternatively, manual port mapping can be specified with the `--publish` or `-p` options, just as when using docker run:
   	```console
   	$ docker compose run --publish 8080:80 -p 2022:22 -p 127.0.0.1:2021:21 web python manage.py shell
   	```

Related issue

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