Fix WorkflowExecutor initialization error (E0599)

[yabhimanyu2007-sys]

Summary

Fixes a compilation error caused by the use of WorkflowExecutor::default() which is not implemented.

Changes

• Replaced WorkflowExecutor::default() with WorkflowExecutor::new(ExecutorConfig::default())

Context

The previous implementation attempted to call a non-existent default() method on WorkflowExecutor, leading to Rust error E0599.

Result

• Project builds successfully
• All tests pass without failures

How to Test

1. Run cargo build
2. Run cargo test
3. Verify no compilation errors occur

Breaking Changes

• None

Notes

This change aligns with the current design of WorkflowExecutor and ensures compatibility with the existing API.

[SH20RAJ]

Hey @yangrudan @lijingrs, could you please review this PR? It fixes a WorkflowExecutor initialization error (E0599) that likely affects users. Thanks! 👀

[yabhimanyu2007-sys]

Reproduction

While building the project, I encountered a compilation error:

error[E0599]: no function or associated item named default found for WorkflowExecutor

This occurs where "WorkflowExecutor::default()" is used.

Fix

Replaced "WorkflowExecutor::default()" with "WorkflowExecutor::new()", which aligns with the current API.

Verification

• "cargo build" completes successfully
• "cargo test" passes without errors

Please let me know if this change aligns with the intended usage or if additional adjustments/tests are needed.