Opening Session from Filesystem uses that Filesystem Incorrectly

[pati08]

2. Issues with the Zellij UI / behavior / crash

Issue description

When using zellij, there are cases where it can erroneously prevent unmounting a device.

Minimal reproduction

1. Attach to a dead session (or maybe create a new one) from a mountpoint. Make sure that no process, shell, etc in that zellij session is using that directory.
2. Detach and exit the mountpoint directory in your shell
3. Attempt to unmount the device and see the error.

Other relevant information

Using fish shell and NixOS