ref: clean old files

[marandaneto]

💡 Motivation and Context

Release log:

Total compressed archive size: 85 KB.
Validating package...
Package validation found the following potential issue:

• 2 checked-in files are ignored by a .gitignore.
  Previous versions of Pub would include those in the published package.

  Consider adjusting your .gitignore files to not ignore those files, and if you do not wish to
  publish these files use .pubignore. See also dart.dev/go/pubignore

  Files that are checked in while gitignored:

  example/android/app/src/debug/AndroidManifest.xml
  example/ios/Podfile.lock

They don't need to be checked in.
Strange enough, example/android/app/src/debug/AndroidManifest.xml isn't ignored and has to be checked in, likely a bug in the analyzer.

#skip-changelog

💚 How did you test it?

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

[marandaneto]

Its always build/ and its already ignored, likely an old gitignore file

[marandaneto]

this is auto generated anyways

[pauldambra]

🚢