ci: Create screenshots with `@storybook/test-runner`

What does this MR do?

Apparently @storybook/test-runner is a jest and playwright based test runner which allows us to test our storybook stories and create snapshots of them. The benefit of this package over @storybook/addon-storyshots, is that each story becomes it's own test. That means that jest is able to parallelise tests run with workers.

Furthermore it has a --shard parameter to further parallelise tests across multiple jobs, similar to the playwright parameter with the same name.

This commit introduces the dependency and utilizes them in new jobs: visual and update_screenshots. The old corresponding puppeteer jobs have been renamed with an old prefix.

Future improvements:

• Remove storyshots, it's expectations and everything related
• Enable more browsers (firefox, webkit)
• Change our puppeteer image to become a playwright image
• Consider migrating our few integration tests to playwright

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines.
• GitLab UI's contributing guidlines.
• If it changes a Pajamas-compliant component's look & feel, the MR has been reviewed by a UX designer.
• If it changes GitLab UI's documentation guidelines, the MR has been reviewed by a Technical Writer.
• If the MR changes a component's API, integration MR(s) have been opened in the following projects to ensure that the @gitlab/ui package can be upgraded quickly after the changes are released:
  • GitLab: mr_url
  • CustomersDot: mr_url
  • Status Page: mr_url
• Added the ~"component:*" label(s) if applicable.

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• Security reports checked/validated by a reviewer from the AppSec team

Accessibility

If this MR adds or modifies a component, take a few moments to review the following:

• All actions and functionality can be done with a keyboard.
• Links, buttons, and controls have a visible focus state.
• All content is presented in text or with a text equivalent. For example, alt text for SVG, or aria-label for icons that have meaning or perform actions.
• Changes in a component’s state are announced by a screen reader. For example, changing aria-expanded="false" to aria-expanded="true" when an accordion is expanded.
• Color combinations have sufficient contrast.