Add Linux build CI (#7581)

Release Notes:

- N/A

crates/gpui/src/platform/linux/platform.rs

@@ -231,22 +231,6 @@ impl Platform for LinuxPlatform {
         Box::new(LinuxWindow(window_ptr))
     }
 
-    fn set_display_link_output_callback(
-        &self,
-        display_id: DisplayId,
-        callback: Box<dyn FnMut() + Send>,
-    ) {
-        log::warn!("unimplemented: set_display_link_output_callback");
-    }
-
-    fn start_display_link(&self, display_id: DisplayId) {
-        unimplemented!()
-    }
-
-    fn stop_display_link(&self, display_id: DisplayId) {
-        unimplemented!()
-    }
-
     fn open_url(&self, url: &str) {
         unimplemented!()
     }