chore: ignore more test files from being published

[iuioiua]

This change:

1. Includes **/*test.{ts,js} files to be published, as there's https://github.com/denoland/deno_std/blob/main/front_matter/test.ts that is part of the non-testing, public API.
2. Adds further test files, like io/_test_common.ts to be excluded from publishing.

[kt3k]

Good catch! LGTM

[lucacasonato]

Why did we do this? Publishing test files to JSR is not a bad thing. Also this broke publishing of std/expect: _custom_equality_tester.ts matches the ignore regexp.

[kt3k]

Thanks for catching!

Publishing test files to JSR is not a bad thing.

Ok. Let's include test files in published assets.