chore(release): prepare for dart_skills_lint for 0.4.0

[reidbaker-agent]

release binary support and individulal_skills

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene wiki page, which explains my responsibilities.
• I read the Flutter Style Guide recently, and have followed its advice.
• I signed the CLA.
• I listed at least one issue that this PR fixes in the description above.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is test-exempt.
• All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel on Discord.

[gemini-code-assist]

Code Review

This pull request promotes the dart_skills_lint tool from version 0.4.0-dev.1 to the stable 0.4.0 release, updating the version across pubspec.yaml, README.md, and CHANGELOG.md, and removing preview-related references. Feedback was provided on the changelog to expand the brief entry for issue #166 with a short description of the actual fix.

[reidbaker]

not sure why we are stuck on queuing (github outage or org limitation) but all queued tasks pass locally I am going to merge then run through the post release process.