cleanup: dart 3.10, dot shorthands, refactor isSuccess

[jtmcdole]

A number of things:

1. Update to dart 3.10 to allow for dart dot-shorthands
2. Refactor "isBuildSuccessed" and "isBuildFailed" - there is already an isSuccess, isCompleted, and isFailure.

[github-actions]

🤖 Hi @jtmcdole, I've received your request, and I'm working on it now! You can track my progress in the logs for more details.

[jtmcdole]

There is definitely more places we can update / cleanup. I'll probably write a task to do it.

[github-actions]

## 📋 Review Summary

This pull request successfully refactors TaskStatus and TaskConclusion states to consolidate checks for success, completion, and failure statuses while bringing in Dart 3.10 features. However, several critical compile-time errors have been identified where dot shorthand (.enumValue) is improperly used in combination with the equality (== and !=) operators.

🔍 General Feedback

• Dot Shorthand Limitations: The == and != operators in Dart take an Object as a parameter. Because of this, they do not provide an expected context type to the right-hand side operand, rendering dot shorthand invalid and causing compile-time errors.
• Enum Lexical Scope: As a general rule when working within an enum block, its constants are already available in lexical scope, so you can just use constantName without qualification or dot shorthand (e.g., success instead of .success or TaskConclusion.success).
• Use Switch Expressions: The refactoring to use switch (this) for boolean status getters (like isSuccess and isFailure) is clean, idiomatic Dart 3 code that leverages pattern matching. Where applicable, switch blocks provide the required context type that makes dot shorthand perfectly valid and should be used instead of chained equality checks.

[ievdokdm]

LGTM