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 * the `gst-validate` tarball has been superseded by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/libraries/gstreamer/core/default.nix

@@ -1,6 +1,5 @@
 { stdenv
 , fetchurl
-, fetchpatch
 , meson
 , ninja
 , pkgconfig
@@ -16,34 +15,30 @@
 , darwin
 , elfutils # for libdw
 , bash-completion
-, docbook_xsl
-, docbook_xml_dtd_43
-, gtk-doc
 , lib
 , CoreServices
 }:
 
 stdenv.mkDerivation rec {
   pname = "gstreamer";
-  version = "1.16.2";
+  version = "1.18.0";
 
-  outputs = [ "out" "dev" "devdoc" ];
+  outputs = [
+    "out"
+    "dev"
+    # "devdoc" # disabled until `hotdoc` is packaged in nixpkgs, see:
+    # - https://github.com/NixOS/nixpkgs/pull/98767
+    # - https://github.com/NixOS/nixpkgs/issues/98769#issuecomment-702296551
+  ];
   outputBin = "dev";
 
   src = fetchurl {
     url = "${meta.homepage}/src/${pname}/${pname}-${version}.tar.xz";
-    sha256 = "0kp93622y29pck8asvil1fmzf55s2gx76wv475a6izc3cwj49w73";
+    sha256 = "01bq1k0gj603zyhq975zl09q4zla12mxqvhmk9fyn2kcn12r5w0g";
   };
 
   patches = [
     ./fix_pkgconfig_includedir.patch
-
-    # Fix build with bash-completion 2.10
-    # https://gitlab.freedesktop.org/gstreamer/gstreamer/merge_requests/436
-    (fetchpatch {
-      url = "https://gitlab.freedesktop.org/gstreamer/gstreamer/commit/dd2ec3681e2d38e13e01477efa36e851650690fb.patch";
-      sha256 = "07hwf67vndsibm1khvs4rfq30sbs9fss8k5vs502xc0kccbi1ih8";
-    })
   ];
 
   nativeBuildInputs = [
@@ -60,9 +55,7 @@ stdenv.mkDerivation rec {
     bash-completion
 
     # documentation
-    gtk-doc
-    docbook_xsl
-    docbook_xml_dtd_43
+    # TODO add hotdoc here
   ];
 
   buildInputs = [
@@ -82,6 +75,7 @@ stdenv.mkDerivation rec {
   mesonFlags = [
     "-Ddbghelp=disabled" # not needed as we already provide libunwind and libdw, and dbghelp is a fallback to those
     "-Dexamples=disabled" # requires many dependencies and probably not useful for our users
+    "-Ddoc=disabled" # `hotdoc` not packaged in nixpkgs as of writing
   ] ++ lib.optionals stdenv.isDarwin [
     # darwin.libunwind doesn't have pkgconfig definitions so meson doesn't detect it.
     "-Dlibunwind=disabled"
@@ -93,7 +87,8 @@ stdenv.mkDerivation rec {
       gst/parse/get_flex_version.py \
       gst/parse/gen_grammar.py.in \
       gst/parse/gen_lex.py.in \
-      libs/gst/helpers/ptp_helper_post_install.sh
+      libs/gst/helpers/ptp_helper_post_install.sh \
+      scripts/extract-release-date-from-doap-file.py
   '';
 
   postInstall = ''