Unable to configure ci with local gitlab instance and local gitlab-runner both docker

I am trying to do some research for our company since we want to switch to docker.
The Problem now is that i got a local gitlab instance for testing and wanted to try the gitlab ci feature and how i have to configure everything.
I can register a new runner but when running a pipeline it always gets stuck and it seems that gitlab can’t communicate with the runner.
This is my current runner configuration:

check_interval = 0
log_level = "debug"

[session_server]
  session_timeout = 1800

[[runners]]
  name = "test"
  url = "http://gitlab" // the name of the gitlab instance in my docker-compose
  token = "xxx"
  executor = "docker"
  [runners.docker]
    tls_verify = false
    image = "docker:stable"
    privileged = false
    disable_entrypoint_overwrite = false
    oom_kill_disable = false
    disable_cache = false
    volumes = ["/cache"]
    shm_size = 0
  [runners.cache]
    [runners.cache.s3]
    [runners.cache.gcs]

my docker-compose file:

version: "3"
services:
  gitlab:
    image: gitlab/gitlab-ce
    hostname: "gitlab.local"
    volumes:
    - ./logs:/var/log/gitlab
    - ./gitlab:/var/opt/gitlab
    - ./etc/gitlab:/etc/gitlab
    labels:
      traefik.enable: "true"
      traefik.frontend.rule: "Host:gitlab.local"
      traefik.network: "traefik"
      traefik.backend: "gitlab"
      traefik.frontend.entrypoint: "http"
      traefik.port: "80"
    networks:
    - traefik
  gitlab-runner:
    image: gitlab/gitlab-runner:latest
    container_name: gitlab-runner
    restart: always
    volumes:
      - ./runner-config:/etc/gitlab-runner
      - /var/run/docker.sock:/var/run/docker.sock
    labels:
      traefik.enable: "true"
      traefik.frontend.rule: "Host:gitlab-runner.local"
      traefik.network: "traefik"
      traefik.backend: "gitlab-runner"
      traefik.frontend.entrypoint: "http"
      traefik.port: "80"
    networks:
    - traefik
networks:
  traefik:
    external: true

Hi !
I have the same problem, do you find a solution?