This PR refactors numerous lambda expressions by removing unnecessary braces and streamlining single-statement lambdas throughout the codebase, improving readability and maintainability.
- Consider simplifying lambda when its body has a single statement: DeepSource flagged lambdas written with a block body for only one statement, causing extra verbosity. This update converts those to concise expression-bodied lambdas by stripping out the curly braces, applied across test assertions, event registrations, and unregister logic. The code is now cleaner and more consistent.
> This Autofix was generated by AI. Please review the change before merging.
