Issue #, if available:

Fixes #1543

Description of changes:

The ServiceException constructor was not assigning $retryable or $response from the options parameter, even though both properties are declared on the class and defined in the ServiceExceptionOptions type (via SmithyException).

This meant that constructing a ServiceException (or subclass) with $retryable or $response in the options object would silently drop those values.

const error = new ServiceException({
  name: "TestError",
  $fault: "client",
  $metadata: {},
  $retryable: { throttling: true },
});

error.$retryable; // was: undefined, now: { throttling: true }

The fix adds the two missing assignments in the constructor alongside the existing ones for $fault and $metadata.

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