gphoto2: remove patch already applied upstream (#380232)

pkgs/applications/misc/gphoto2/add-type-casts.diff

@@ -1,21 +0,0 @@
-diff --git a/gphoto2/main.c b/gphoto2/main.c
-index 2bf5964..cd84467 100644
---- a/gphoto2/main.c
-+++ b/gphoto2/main.c
-@@ -1215,14 +1215,14 @@ start_timeout_func (Camera *camera, unsigned int timeout,
- 
- 	pthread_create (&tid, NULL, thread_func, td);
- 
--	return (tid);
-+	return (unsigned int)tid;
- }
- 
- static void
- stop_timeout_func (Camera __unused__ *camera, unsigned int id,
- 		   void __unused__ *data)
- {
--	pthread_t tid = id;
-+	pthread_t tid = (pthread_t)id;
- 
- 	pthread_cancel (tid);
- 	pthread_join (tid, NULL);

pkgs/applications/misc/gphoto2/default.nix

@@ -24,8 +24,6 @@ stdenv.mkDerivation rec {
     sha256 = "sha256-t5EnM4WaDbOTPM+rJW+hQxBgNErnnZEN9lZvxTKoDhA=";
   };
 
-  patches = [ ./add-type-casts.diff ];
-
   nativeBuildInputs = [
     autoreconfHook
     pkg-config