How to run Selenium sind runner in GitLabCI?

Question

I'm currently evaluating Selenium in combination with GitLab CI as a testing tool for our website. This is my current .gitlab-ci.yml:

variables:
    GIT_STRATEGY: clone
    GIT_DEPTH: 0

stages:
    - tests

test:
    stage: tests
    image: node:latest
    tags:
        - linux
    before_script:
        - apt-get update
        - apt-get install -y chromium
        - npm install -g selenium-side-runner
        - npm install -g chromedriver
    script:
        - selenium-side-runner My-UI-Test.side

I'm getting the following error:

FAIL ./DefaultSuite.test.js
  ● Test suite failed to run
    WebDriverError: unknown error: Chrome failed to start: exited abnormally.
      (unknown error: DevToolsActivePort file doesn't exist)
      (The process started from chrome location /usr/bin/chromium is no longer running, so ChromeDriver is assuming that Chrome has crashed.)
      at Object.throwDecodedError (../../../../../../usr/local/lib/node_modules/selenium-side-runner/node_modules/selenium-webdriver/lib/error.js:550:15)
      at parseHttpResponse (../../../../../../usr/local/lib/node_modules/selenium-side-runner/node_modules/selenium-webdriver/lib/http.js:560:13)
      at Executor.execute (../../../../../../usr/local/lib/node_modules/selenium-side-runner/node_modules/selenium-webdriver/lib/http.js:486:26)

I've searched for the error message DevToolsActivePort file doesn't exist and it seems that Chrome doesn't like to be run with root privileges. A lot of answers suggest using the --no-sandbox or --disable-dev-shm-usage flags. But those are Chrome flags, and since I'm not calling Chrome directly, I can't use them. The website in question is also deployed from a different project, so I have no code to work with. The only files I can change are My-UI-Test.side and .side.yaml.