Dashboard Permissions bug

When a dashboard is set to readonly, it is unable to be changed to a global shared dashboard. It is still possible to change it to private.

Also, creating a new dashboard defaults to shared(read) even though I set it to be shared(edit).

This was tested on multiple browsers and confirmed by Laf in discord.

Working on the fix (Already fixed but PR is not pushed yet)

Please, test https://github.com/librenms/librenms/pull/9236

Looks like it worked. Thanks!