deadcode in eventloops.py

```
    from IPython.external.qt_for_kernel import QtCore

    if _use_appnope() and kernel._darwin_app_nap:
        from appnope import nope_scope as context
    else:
        from contextlib import contextmanager
        @contextmanager
        def context():
            yield
```

`context` seem to be unused in rest of the file.