[Homescreen codelab] Update dependencies

[wrbl606]

• Update home_widget to 0.6.0, which adds support for Flutter 3.20+
• Bump Kotlin version of the Android project as the fix suggests (see the message below)

┌─ Flutter Fix ──────────────────────────────────────────────────────────────────────────────────────┐
│ [!] Your project requires a newer version of the Kotlin Gradle plugin.                             │
│ Find the latest version on https://kotlinlang.org/docs/releases.html#release-details, then update  │
│ /Users/marcinwroblewski/Documents/Projects/flutter-codelabs/homescreen_codelab/step_03/android/bui │
│ ld.gradle:                                                                                         │
│ ext.kotlin_version = '<latest-version>'                                                            │
└────────────────────────────────────────────────────────────────────────────────────────────────────┘

Pre-launch Checklist

• I read the Effective Dart: Style recently, and have followed its advice.
• I signed the CLA.
• I updated/added relevant documentation (doc comments with ///).
• All existing and new tests are passing.

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[wrbl606]

Tests for Windows have failed, marking the checks as failed, but I don't think my changes caused that. It looks like the Flutter installation step has issues, can we circumvent the check and merge this to main or do I have to debug the Windows workflow?

[parlough]

Tests for Windows have failed, marking the checks as failed, but I don't think my changes caused that. It looks like the Flutter installation step has issues, can we circumvent the check and merge this to main or do I have to debug the Windows workflow?

No need worry about the unrelated Windows failure, but thanks for thinking about it :) - I've opened a fix in flutter/flutter#150314.

Thanks again for the PR. I'll leave landing the change to @ericwindmill though so he is aware of the update.

[auto-submit]

auto label is removed for flutter/codelabs/2210, due to - The status or check suite Test Flutter beta on windows-latest has failed. Please fix the issues identified (or deflake) before re-applying this label.