haskell.packages.ghc96.gi-gtk: Work around compiler issue

When building gi-gtk with ghc-9.6.1 and ghc-9.6.2 there are errors
like this:

  <no location info>: error:
  attempting to use module ‘gi-gtk-3.0.41-DcfU7A0rbDCAyPkJQEwKC:GI.Gtk.Interfaces.Buildable’ (./GI/Gtk/Interfaces/Buildable.hs) which is not loaded

The errors can be avoided by using -j1, which is unfortunate for
gi-gtk because it has 708 modules to build.

The ghc gitlab issue is: https://gitlab.haskell.org/ghc/ghc/-/issues/23392

pkgs/development/haskell-modules/configuration-ghc-9.6.x.nix

@@ -14,6 +14,9 @@ let
     else
       builtins.throw "Check if '${msg}' was resolved in ${pkg.pname} ${pkg.version} and update or remove this";
   jailbreakForCurrentVersion = p: v: checkAgainAfter p v "bad bounds" (doJailbreak p);
+
+  # Workaround for a ghc-9.6 issue: https://gitlab.haskell.org/ghc/ghc/-/issues/23392
+  disableParallelBuilding = overrideCabal (drv: { enableParallelBuilding = false; });
 in
 
 self: super: {
@@ -207,7 +210,6 @@ self: super: {
     gi-glib
     gi-gmodule
     gi-gobject
-    gi-gtk
     gi-harfbuzz
     gi-pango
     gi-xlib
@@ -219,6 +221,9 @@ self: super: {
     taffybar
   ;
 
+  # Avoid triggering an issue in ghc-9.6.2
+  gi-gtk = disableParallelBuilding (__CabalEagerPkgConfigWorkaround super.gi-gtk);
+
   # Pending text-2.0 support https://github.com/gtk2hs/gtk2hs/issues/327
   gtk = doJailbreak super.gtk;