[fix] `:last-child` doesn't want parentheses

[domq]

Source: https://developer.mozilla.org/fr/docs/Web/CSS/:last-child + whining from esbuild.

Fixes #700

[github-actions[bot]]

Unit Test Results

    1 files      1 suites   0s :stopwatch: 267 tests 259 :heavy_check_mark: 0 :zzz: 0 :x: 8 :fire: 267 runs  251 :heavy_check_mark: 0 :zzz: 8 :x: 8 :fire:

For more details on these errors, see this check.

Results for commit fd8e7cad.

[github-actions[bot]]

🔎 Download the Backstop report for this pull request (link valid for 90 days):

• backstop-report.zip