Disable pacman command-not-found handler

Apparently it's too slow on some systems

Fixes #7841.

(cherry picked from commit 95dc821a44)

share/functions/fish_command_not_found.fish

@@ -57,17 +57,18 @@ else if type -q pkgfile
             __fish_default_command_not_found_handler $argv[1]
         end
     end
-else if type -q pacman
-    function fish_command_not_found
-        set -l paths $argv[1]
-        # If we've not been given an absolute path, try $PATH as the starting point,
-        # otherwise pacman will try *every path*, and e.g. bash-completion
-        # isn't helpful.
-        string match -q '/*' -- $argv[1]; or set paths $PATH/$argv[1]
-        # Pacman only prints the path, so we still need to print the error.
-        __fish_default_command_not_found_handler $argv[1]
-        pacman -F $paths
-    end
+# pacman is too slow, see #7841.
+# else if type -q pacman
+#     function fish_command_not_found
+#         set -l paths $argv[1]
+#         # If we've not been given an absolute path, try $PATH as the starting point,
+#         # otherwise pacman will try *every path*, and e.g. bash-completion
+#         # isn't helpful.
+#         string match -q '/*' -- $argv[1]; or set paths $PATH/$argv[1]
+#         # Pacman only prints the path, so we still need to print the error.
+#         __fish_default_command_not_found_handler $argv[1]
+#         pacman -F $paths
+#     end
 else
     # Use standard fish command not found handler otherwise
     function fish_command_not_found --on-event fish_command_not_found