linux: Ignore benign error when cancelling file picker (#15553)

Fixes https://github.com/zed-industries/zed/issues/15485

This should be clearer on the `ashpd` side, but `ResponseError` comes
from the portal
[Response](https://flatpak.github.io/xdg-desktop-portal/docs/doc-org.freedesktop.portal.Request.html#org-freedesktop-portal-request-response),
which means the request itself didn't fail. Ignoring the `Other` variant
here should be safe.

Release Notes:

- Linux: Fixed benign error being shown when cancelling file picker
([#15485](https://github.com/zed-industries/zed/issues/15485))