crashhandler: Cast rptdir to Path (#14578)...
crashhandler: Cast rptdir to Path (#14578)
Previously `self.app.ipython_dir` is a string, which makes
`Path.is_dir(<object>)` fail. Note that the argument is `self` i.e.
should be a `Path` instance.
If `ipython_dir` is `None` then this code would just catch it in the
`except:` branch, which makes it be set to `Path.cwd()` anyway.
