opencv: 4.11.0 -> 4.12.0

https://github.com/opencv/opencv/wiki/OpenCV-Change-Logs#version4120
opencv/opencv@4.11.0...4.12.0

Author: mweinelt

pkgs/development/libraries/opencv/4.x.nix

@@ -103,7 +103,7 @@ let
     ;
   inherit (lib.trivial) flip;
 
-  version = "4.11.0";
+  version = "4.12.0";
 
   # It's necessary to consistently use backendStdenv when building with CUDA
   # support, otherwise we get libstdc++ errors downstream
@@ -114,7 +114,7 @@ let
     owner = "opencv";
     repo = "opencv";
     tag = version;
-    hash = "sha256-oiU4CwoMfuUbpDtujJVTShMCzc5GsnIaprC4DzkSzEM=";
+    hash = "sha256-TZdEeZyBY3vCI53g4VDMzl3AASMuXAZKrSH/+XlxR7c=";
   };
 
   contribSrc = fetchFromGitHub {