gtk and gtk-sys need updated in Cargo.toml

[hwittenborn]

gtk and gtk-sys aren't currently on the latest version, which is causing an issue in my project when updating the version of gtk used in my project: hwittenborn/celeste#82 (comment).

I also saw that Renovate is used in the main Tauri repository, but it doesn't appear to be being used here. Maybe that could be added here too so these kind of issues aren't needed?

[esimkowitz]

Necroing this, gtk-sys is deprecated and there's a security advisory for the glib version that it depends on: GHSA-wrw7-89jp-8q8g

This project should be updated to use gtk4-rs instead

[amrbashir]

libappindicator/libayatana-appindicatr doesn't support gtk4 see AyatanaIndicators/libayatana-appindicator#22

However, Tauri ecosystem will soon migrate to gtk4 because of said CVE and will instead use KDE/freedesktop StatusNotifierItem specification for tray icons instead of libappindicator, see tauri-apps/tray-icon#201