gstreamer: 1.16.2 -> 1.18.0

Fixes #98769.

Important changes from https://gstreamer.freedesktop.org/releases/1.18/:

* `gst-validate` was renamed to `gst-devtools` upstream:

    > * the `gst-validate` tarball has been superseded by
    >   the `gst-devtools` tarball for consistency with the git module name.

* `gst-python` is now Python 3 only:

    > * Python 2.x is no longer supported

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

@@ -4,17 +4,16 @@
 , ninja
 , stdenv
 , pkgconfig
-, python
+, python3
 , pygobject3
 , gobject-introspection
 , gst-plugins-base
 , isPy3k
-, fetchpatch
 }:
 
 buildPythonPackage rec {
   pname = "gst-python";
-  version = "1.16.2";
+  version = "1.18.0";
 
   format = "other";
 
@@ -22,14 +21,17 @@ buildPythonPackage rec {
 
   src = fetchurl {
     url = "${meta.homepage}/src/gst-python/${pname}-${version}.tar.xz";
-    sha256 = "1a48ca66izmm8hnp608jv5isg3jxb0vlfmhns0bg9nbkilag7390";
+    sha256 = "0ifx2s2j24sj2w5jm7cxyg1kinnhbxiz4x0qp3gnsjlwbawfigvn";
   };
 
+  # Python 2.x is not supported.
+  disabled = !isPy3k;
+
   nativeBuildInputs = [
     meson
     ninja
     pkgconfig
-    python
+    python3
     gobject-introspection
     gst-plugins-base
   ];
@@ -39,24 +41,8 @@ buildPythonPackage rec {
     pygobject3
   ];
 
-  patches = stdenv.lib.optionals stdenv.isDarwin [
-    # Fix configure python lib detection in macOS. Remove with the next release
-    (fetchpatch {
-      url = "https://github.com/GStreamer/gst-python/commit/f98c206bdf01529f8ea395a719b10baf2bdf717f.patch";
-      sha256 = "04n4zrnfivgr7iaqw4sjlbd882s8halc2bbbhfxqf0sg2lqwmrxg";
-    })
-  ] ++ [
-    # Fix linking against Python 3.8
-    # https://gitlab.freedesktop.org/gstreamer/gst-python/merge_requests/30
-    (fetchpatch {
-      url = "https://gitlab.freedesktop.org/gstreamer/gst-python/commit/22f28155d86e27c4134de4ed2861264003fcfd23.patch";
-      sha256 = "Y70qVguHUBmmRVMFBKAP0d6anBQw5W0TKyu2bAwxbQg=";
-    })
-  ];
-
   mesonFlags = [
-    "-Dpython=python${if isPy3k then "3" else "2"}"
-    "-Dpygi-overrides-dir=${placeholder "out"}/${python.sitePackages}/gi/overrides"
+    "-Dpygi-overrides-dir=${placeholder "out"}/${python3.sitePackages}/gi/overrides"
   ];
 
   doCheck = true;