Updated test definitions across multiple suites to accept and pass abort signals (`signal`) for enhanced request handling. Adjusted the `start` method in the test runner to support optional abort signals.

Reworked `copyExecutionContext` to use a dynamic property descriptor approach, enabling method overrides without altering the original object. Expanded test cases to cover additional methods and verify override behavior.

Enhanced the descriptor logic to better handle non-function properties and prevent invalid method overrides. Fixed potential issues with binding non-function properties to the context.

Updated the `OverridesStore` type to strictly associate keys with context-specific methods, improving type safety. Renamed and enhanced the descriptor creation function to better handle method overriding and added checks for function-only properties.

Added `packages/**/*.junit.xml` to `.gitignore` to prevent JUnit report files from being tracked in the repository, keeping the working directory clean and avoiding unnecessary versioning of test artifacts.