Bring over latest files from flutter/packages

[mit-mit]

As a first step in moving the source location , this PR moves over the latest files from

---

• I’ve reviewed the contributor guide and applied the relevant portions to this PR.

• See our contributor guide for general expectations for PRs.

• Larger or significant changes should be discussed in an issue before creating a PR.

• Contributions to our repos should follow the Dart style guide and use dart format.

• Most changes should add an entry to the changelog and may need to rev the pubspec package version.

• Changes to packages require corresponding tests.

Note that many Dart repos have a weekly cadence for reviewing PRs - please allow for some latency before initial review feedback.

[mit-mit]

$ diff -qr ~/dev/flutter_packages/packages/platform/ .
Only in .: .git
Only in .: .github
Files /Users/mit/dev/flutter_packages/packages/platform/CHANGELOG.md and ./CHANGELOG.md differ
Only in .: CONTRIBUTING.md
Files /Users/mit/dev/flutter_packages/packages/platform/LICENSE and ./LICENSE differ
Only in .: analysis_options.yaml
Only in /Users/mit/dev/flutter_packages/packages/platform: dart_test.yaml
Files /Users/mit/dev/flutter_packages/packages/platform/pubspec.yaml and ./pubspec.yaml differ

$ diff ~/dev/flutter_packages/packages/platform/CHANGELOG.md CHANGELOG.md
3a4,5
> * Transfers the package source from https://github.com/flutter/packages
>   to https://github.com/dart-lang/platform.

$ diff ~/dev/flutter_packages/packages/platform/pubspec.yaml pubspec.yaml
3,4c3,4
< repository: https://github.com/flutter/packages/tree/main/packages/platform
< issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+platform%22
---
> repository: https://github.com/dart-lang/platform
> issue_tracker: https://github.com/dart-lang/platform/issues
10a11
>   lints: ^4.0.0

[mit-mit]

After the diff above, replaced the Flutter example/ with a plain Dart console one.

[stuartmorgan]

LGTM

[stuartmorgan]

I'm not familiar with dart-lang-owned package conventions; is it normal to have a custom analysis options for the example directory?

[lrhn]

I don't know, but I'd expect examples to use lints/recommended, to be written for users using those lints, and the package itself to use dart_flutter_team_lints (or whatever it's called, I can never remember, or seem to find it when I need it).

Could probably use the same lints everywhere, since the dart/flutter team lints includes everything in recommended, and probably won't add many extra restrictions for traditional example code.

[mit-mit]

Wasn't strictly needed before, but now example and package use different lints, so now it's needed

[stuartmorgan]

This should probably use 3.2 like the package itself.

[mit-mit]

Done

[lrhn]

Use dart_flutter_team_lints?
(Not that I prefer them, but they exist now.)

[mit-mit]

Done