Update dependency dart_either to v2

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
dart_either (source)	dependencies	major	^1.0.0 → ^2.0.0

---

Release Notes

hoc081098/dart_either (dart_either)

v2.1.0

Compare Source

• Promoted Either.parSequenceN and Either.parTraverseN from experimental to stable.
• Added complete API docs and examples for Either.parSequenceN and Either.parTraverseN.
• Added unit tests for Either.parSequenceN and Either.parTraverseN, including concurrency-limit and short-circuit cases.
• Added @useResult annotations to public APIs that should not be ignored (for example: isLeft, isRight, map, flatMap, swap, exists, all, toEitherStream, left, right, and others).

API migration notes

• Either.parSequenceN changed from positional parameters to named parameters:

  // Before (2.0.0)
  Either.parSequenceN<String, int>(functions, n);
  
  // Now (2.1.0)
  Either.parSequenceN<String, int>(
    functions: functions,
    maxConcurrent: n,
  );

• Either.parTraverseN changed from positional parameters to named parameters:

  // Before (2.0.0)
  Either.parTraverseN<String, int, int>(values, mapper, n);
  
  // Now (2.1.0)
  Either.parTraverseN<String, int, int>(
    values: values,
    mapper: mapper,
    maxConcurrent: n,
  );

• maxConcurrent controls concurrency.
  • Pass a number (for example 2) to limit concurrency.
  • Pass null for unlimited concurrency.

v2.0.0

Compare Source

• Require Dart 3.0.0 or higher >=3.0.0 <4.0.0.

• Make Either a sealed class, EitherEffect a sealed class, and ControlError a final class.
  Now you can use exhaustive switch expressions on Either instances.

  final Either<String, int> either = Either.right(10);
  
  // Use the `when` method to handle
  either.when(
    ifLeft: (l) => print('Left: $l'),
    ifRight: (r) => print('Right: $r'),
  ); // Prints Right: Either.Right(10)
  
  // Or use Dart 3.0 switch expression syntax 🤘
  print(
    switch (either) {
      Left() => 'Left: $either',
      Right() => 'Right: $either',
    },
  ); // Prints Right: Either.Right(10)

---

Configuration

📅 Schedule: (UTC)

• Branch creation
  • At any time (no schedule defined)
• Automerge
  • At any time (no schedule defined)

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• If you want to rebase/retry this PR, check this box

---

This PR was generated by Mend Renovate. View the repository job log.

[renovate]

⚠️ Artifact update problem

Renovate failed to update an artifact related to this branch. You probably do not want to merge this PR as-is.

♻ Renovate will retry this branch, including artifacts, only when one of the following happens:

• any of the package files in this branch needs updating, or
• the branch becomes conflicted, or
• you click the rebase/retry checkbox if found above, or
• you rename this PR's title to start with "rebase!" to trigger it manually

The artifact failure details are included below:

File name: pubspec.lock

Command failed: flutter pub upgrade dart_either
Because rxdart_ext 0.2.9 depends on dart_either ^1.0.0 and no versions of rxdart_ext match >0.2.9 <0.3.0, rxdart_ext ^0.2.9 requires dart_either ^1.0.0.
So, because batch_api_demo depends on both rxdart_ext ^0.2.9 and dart_either ^2.0.0, version solving failed.


You can try one of the following suggestions to make the pubspec resolve:
* Consider downgrading your constraint on rxdart_ext: flutter pub add rxdart_ext:^0.2.5
* Consider downgrading your constraint on dart_either: flutter pub add dart_either:^1.0.0
Failed to update packages.