qstopmotion: use ffmpeg instead of ffmpeg_3 (#123477)

FFmpeg isn't linked against, but the executable is used for rendering.

pkgs/applications/video/qstopmotion/default.nix

@@ -6,7 +6,7 @@
 , qtquickcontrols
 , qtimageformats
 , qtxmlpatterns
-, ffmpeg_3
+, ffmpeg
 , guvcview
 , cmake
 , ninja
@@ -40,7 +40,6 @@ mkDerivation rec {
     v4l-utils
     libv4l
     pcre
-    ffmpeg_3
     guvcview
     qwt
   ];
@@ -64,6 +63,10 @@ mkDerivation rec {
     grep -rl 'qwt' . | xargs sed -i 's@<qwt/qwt_slider.h>@<qwt_slider.h>@g'
   '';
 
+  qtWrapperArgs = [
+    "--prefix" "PATH" ":" (lib.makeBinPath [ ffmpeg ])
+  ];
+
   meta = with lib; {
     homepage = "http://www.qstopmotion.org";
     description = "Create stopmotion animation with a (web)camera";