plex-desktop: inherit pname, meta, and enable update.sh

Replaces #328708 and closes https://github.com/NixOS/nixpkgs/issues/345618

pkgs/by-name/pl/plex-desktop/package.nix

@@ -121,7 +121,7 @@ let
   };
 in
 buildFHSEnv {
-  name = "${pname}-${version}";
+  inherit pname version meta;
   targetPkgs = pkgs: [ xkeyboard_config ];
 
   extraInstallCommands = ''
@@ -152,4 +152,5 @@ buildFHSEnv {
     ${lib.toShellVars extraEnv}
     exec ${plex-desktop}/Plex.sh
   '';
+  passthru.updateScript = ./update.sh;
 }

pkgs/by-name/pl/plex-desktop/update.sh

@@ -73,6 +73,7 @@ sed --regexp-extended \
 # try to build the updated version
 #
 
+export NIXPKGS_ALLOW_UNFREE=1
 if ! nix-build -A plex-desktop "$nixpkgs"; then
   echo "The updated plex-desktop failed to build."
   exit 1