Closes #48169

Before you mark this PR as ready for review, make sure that you have:
- [ ] Added a solid test coverage and/or screenshots from doing manual
testing
- [x] Done a self-review taking into account security and performance
aspects
- [ ] Aligned any UI changes with the [UI
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)

Release Notes:

- Fixed "No Apps Available" dialog when opening URIs on Linux/Wayland

Swaps the order of `open_uri_internal` function: try xdg-open first, and
only fall back to the portal if every candidate command fails.

Build Tests:
I tested the build on Arch Linux & MacOS Tahoe and there were no issues.
No error logs when opening repo links.