Ignore paths in .gitignore for Stylelint

[karlhorky]

If Playwright has generated a report, this causes Stylelint failures (see below). Instead we should ignore files using .gitignore for Stylelint.

$ preflight
🚀 UpLeveled Preflight v8.0.1
√ All changes committed to Git
√ node_modules/ folder ignored in Git
√ No extraneous files committed to Git
√ No secrets committed to Git
√ Use single package manager
√ Project folder name matches correct format
√ No dependency problems
√ GitHub repo has deployed project link under About
√ ESLint
× Stylelint
  › Stylelint problems found in the following files:
  playwright\report\trace\codeMirrorModule.ez37Vkbh.css
  playwright\report\trace\inspectorTab.DLjBDrQR.css
  playwright\report\trace\uiMode.CAYqod-m.css
  playwright\report\trace\workbench.D3JVcA9K.css

  Open these files in your editor - there should be problems to fix
√ Prettier
√ ESLint config is latest version
√ Stylelint config is latest version
√ Preflight is latest version

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.