open: Don't run xdg-open in the background

This was introduced as a workaround to #7215 - xdg-open's generic path
wouldn't background graphical apps.

This has been fixed a month ago in xdg-open, so we can stop doing it.

The good news is this also allows terminal apps to be used again, so
it

Fixes #10045

(cherry picked from commit f8e38819a5)

share/functions/open.fish

@@ -24,14 +24,7 @@ if not command -sq open
             end
         else if type -q -f xdg-open
             for i in $argv
-                # In the "generic" path where it doesn't use a helper utility,
-                # xdg-open fails to fork off, so it blocks the terminal.
-                xdg-open $i &
-                # Note: We *need* to pass $last_pid, or it will disown the last *existing* job.
-                # In case xdg-open forks, that would be whatever else the user has backgrounded.
-                #
-                # Yes, this has a (hopefully theoretical) race of the PID being recycled.
-                disown $last_pid 2>/dev/null
+                xdg-open $i
             end
         else
             echo (_ 'No open utility found. Try installing "xdg-open" or "xdg-utils".') >&2