fix: remove explicit playwright install

[dlockhart]

This was missed when this repo was converted to @brightspace-ui/testing. Our library automatically installs Playwright.

[d2l-github-release-tokens[bot]]

:tada: This PR is included in version 3.0.1 :tada:

The release is available on:

• GitHub release
• npm package (@latest dist-tag)

Your semantic-release bot :package::rocket: