shotwell: Add heif support (#408919)

Add heif support to shotwell (based on PR 212842).

pkgs/by-name/sh/shotwell/package.nix

@@ -35,6 +35,7 @@
   libsecret,
   libportal-gtk3,
   gsettings-desktop-schemas,
+  libheif,
 }:
 
 stdenv.mkDerivation (finalAttrs: {
@@ -87,6 +88,18 @@ stdenv.mkDerivation (finalAttrs: {
     libportal-gtk3
   ];
 
+  postInstall = ''
+    # Pull in HEIF support.
+    # In postInstall to run before gappsWrapperArgsHook.
+    export GDK_PIXBUF_MODULE_FILE="${
+      gnome._gdkPixbufCacheBuilder_DO_NOT_USE {
+        extraLoaders = [
+          libheif.out
+        ];
+      }
+    }"
+  '';
+
   passthru = {
     updateScript = gnome.updateScript {
       packageName = "shotwell";