gnu: gnome-builder: Disable jedi plugin.

As pointed out in #45272, it is broken.

* gnu/packages/gnome.scm (gnome-builder)[#:configure-flags] Add
-Dplugin_jedi=false.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

gnu/packages/gnome.scm

@@ -11876,6 +11876,9 @@ (define-public gnome-builder
                                "-Dplugin_clang=false"
                                "-Dplugin_flatpak=false"
                                "-Dplugin_glade=false"
+                               ;; XXX: This one has been shown not to work in
+                               ;;      <https://issues.guix.gnu.org/45272>
+                               "-Dplugin_jedi=false"
                                ;; ... except this one.
                                "-Dplugin_update_manager=false")
        #:phases