python3Packages.ffmpeg-python: replace ffmpeg_3 with ffmpeg

See https://github.com/NixOS/nixpkgs/issues/120705 for the rationale.
ffmpeg-python doesn't seem to be strongly bound to any ffmpeg version
so we can just migrate away.

pkgs/development/python-modules/ffmpeg-python/default.nix

@@ -2,9 +2,9 @@
 , buildPythonPackage
 , fetchFromGitHub
 , substituteAll
-, ffmpeg_3
+, pytestCheckHook
+, ffmpeg
 , future
-, pytest
 , pytestrunner
 , pytest-mock
 }:
@@ -21,23 +21,20 @@ buildPythonPackage rec {
   };
 
   patches = [
-    (
-      substituteAll {
-        src = ./ffmpeg-location.patch;
-        ffmpeg = ffmpeg_3;
-      }
-    )
+    (substituteAll {
+      src = ./ffmpeg-location.patch;
+      inherit ffmpeg;
+    })
   ];
 
   buildInputs = [ pytestrunner ];
   propagatedBuildInputs = [ future ];
-  checkInputs = [ pytest pytest-mock ];
+  checkInputs = [ pytestCheckHook pytest-mock ];
 
   meta = with lib; {
     description = "Python bindings for FFmpeg - with complex filtering support";
     homepage = "https://github.com/kkroening/ffmpeg-python";
     license = licenses.asl20;
     maintainers = [ maintainers.AluisioASG ];
-    platforms = platforms.all;
   };
 }