zeal: migrate to pkgs/by-name, use qt6

Motivated by qt5.qtwebengine being marked vulnerable (#435067):
- Move package from pkgs/data/documentation to pkgs/by-name/ze/zeal
- Switch from Qt5 to Qt6 as the default
- Remove zeal-qt5 and zeal-qt6 variants in favor of single Qt6 version
- Add aliases for deprecated Qt-specific variants

(cherry picked from commit 0e805d89c1)

pkgs/by-name/ze/zeal/package.nix

@@ -6,21 +6,12 @@
   extra-cmake-modules,
   pkg-config,
   httplib,
-  qtbase,
-  qtimageformats,
-  qtwebengine,
-  qtx11extras,
   libarchive,
   libXdmcp,
   libpthreadstubs,
-  wrapQtAppsHook,
   xcbutilkeysyms,
+  qt6,
 }:
-
-let
-  isQt5 = lib.versions.major qtbase.version == "5";
-
-in
 stdenv.mkDerivation (finalAttrs: {
   pname = "zeal";
   version = "0.7.2";
@@ -36,7 +27,7 @@ stdenv.mkDerivation (finalAttrs: {
     cmake
     extra-cmake-modules
     pkg-config
-    wrapQtAppsHook
+    qt6.wrapQtAppsHook
   ];
 
   buildInputs = [
@@ -44,12 +35,11 @@ stdenv.mkDerivation (finalAttrs: {
     libXdmcp
     libarchive
     libpthreadstubs
-    qtbase
-    qtimageformats
-    qtwebengine
+    qt6.qtbase
+    qt6.qtimageformats
+    qt6.qtwebengine
     xcbutilkeysyms
-  ]
-  ++ lib.optionals isQt5 [ qtx11extras ];
+  ];
 
   cmakeFlags = [
     (lib.cmakeBool "ZEAL_RELEASE_BUILD" true)
@@ -68,6 +58,6 @@ stdenv.mkDerivation (finalAttrs: {
       peterhoeg
     ];
     mainProgram = "zeal";
-    inherit (qtbase.meta) platforms;
+    inherit (qt6.qtbase.meta) platforms;
   };
 })

pkgs/top-level/aliases.nix

@@ -2117,6 +2117,8 @@ mapAliases {
   z3_4_8 = throw "'z3_4_8' has been removed in favour of the latest version. Use 'z3'."; # Added 2025-05-18
   zabbix50 = throw "'zabbix50' has been removed, it would have reached its End of Life a few days after the release of NixOS 25.05. Consider upgrading to 'zabbix60' or 'zabbix70'.";
   zabbix64 = throw "'zabbix64' has been removed because it reached its End of Life. Consider upgrading to 'zabbix70'.";
+  zeal-qt5 = lib.warnOnInstantiate "'zeal-qt5' has been removed from nixpkgs. Please use 'zeal' instead" zeal; # Added 2025-08-31
+  zeal-qt6 = lib.warnOnInstantiate "'zeal-qt6' has been renamed to 'zeal'" zeal; # Added 2025-08-31
   zeroadPackages = recurseIntoAttrs {
     zeroad = lib.warnOnInstantiate "'zeroadPackages.zeroad' has been renamed to 'zeroad'" zeroad; # Added 2025-03-22
     zeroad-data = lib.warnOnInstantiate "'zeroadPackages.zeroad-data' has been renamed to 'zeroad-data'" zeroad-data; # Added 2025-03-22

pkgs/top-level/all-packages.nix

@@ -11922,12 +11922,6 @@ with pkgs;
     inherit (plasma5Packages) breeze-icons;
   };
 
-  zeal-qt5 = libsForQt5.callPackage ../data/documentation/zeal { };
-  zeal = zeal-qt5;
-  zeal-qt6 = qt6Packages.callPackage ../data/documentation/zeal {
-    qtx11extras = null; # Because it does not exist in qt6
-  };
-
   ### APPLICATIONS / GIS
 
   qgis-ltr = callPackage ../applications/gis/qgis/ltr.nix { };