build(deps-dev): bump @web/test-runner from 0.19.0 to 0.20.2

Bumps [@web/test-runner](https://github.com/modernweb-dev/web/tree/HEAD/packages/test-runner) from 0.19.0 to 0.20.2.
- [Release notes](https://github.com/modernweb-dev/web/releases)
- [Changelog](https://github.com/modernweb-dev/web/blob/master/packages/test-runner/CHANGELOG.md)
- [Commits](https://github.com/modernweb-dev/web/commits/@web/test-runner@0.20.2/packages/test-runner)

---
updated-dependencies:
- dependency-name: "@web/test-runner"
  dependency-version: 0.20.2
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package-lock.json

@@ -77,7 +77,7 @@
     "@types/chai": "5.2.2",
     "@types/mocha": "10.0.10",
     "@web/dev-server-esbuild": "0.4.3",
-    "@web/test-runner": "0.19.0",
+    "@web/test-runner": "0.20.2",
     "@web/test-runner-commands": "0.9.0",
     "@web/test-runner-playwright": "0.11.1",
     "autoprefixer": "10.4.21",