[12.x] Add some tests coverage for Queue Exception handling

[roshandelpoor]

This PR enhances the test coverage for queue exception handling by adding several new test cases to QueueExceptionTest.php. The additions provide more thorough testing of exception behavior and edge cases.

• test_timeout_exception_can_be_converted_to_string:
  Tests that the TimeoutExceededException can be properly converted to a string representation.
• test_max_attempts_exception_can_be_converted_to_string:
  Tests that the MaxAttemptsExceededException can be properly converted to a string representation.
• test_exceptions_preserve_job_instance:
  Verifies that both exception types properly preserve and expose the job instance that caused the exception, and confirms the type safety of the job property.
• test_custom_job_name_resolution:
  Tests the exception behavior with a custom job name by using an anonymous class that extends MyFakeRedisJob with a different name resolution.

Benefits:

• Increased test coverage for queue exception handling
• Better validation of exception message formatting
• Improved verification of job instance handling
• Added coverage for custom job name scenarios

[taylorotwell]

I think it's OK. Some of these tests just feel a bit like noise.