kdePackages.extra-cmake-modules: don't pull in qdoc

mkKdeDerivation {

  pname = "extra-cmake-modules";

  # Don't depend on qdoc (leaks everywhere, causes random cross issues), we don't install the docs anyway

  # Upstream PR: https://invent.kde.org/frameworks/extra-cmake-modules/-/merge_requests/534

  patches = [ ./no-qdoc.patch ];

  outputs = [ "out" ];

  propagatedNativeBuildInputs = [

diff --git a/modules/ECMGenerateQDoc.cmake b/modules/ECMGenerateQDoc.cmake

index b6d64783314de790a5444c3c0d125b8e455883d9..68c570506fdc118ddef6249bce78051569298b4c 100644

--- a/modules/ECMGenerateQDoc.cmake

+++ b/modules/ECMGenerateQDoc.cmake

@@ -55,8 +55,13 @@ add_custom_target(generate_qch)

 add_custom_target(install_qch_docs)

 function(ecm_generate_qdoc target qdocconf_file)

-    find_package(Qt6Tools CONFIG REQUIRED)

-    find_package(Qt6 COMPONENTS ToolsTools CONFIG REQUIRED)

+    find_package(Qt6Tools CONFIG QUIET)

+    find_package(Qt6 OPTIONAL_COMPONENTS ToolsTools CONFIG QUIET)

+

+    if (NOT Qt6Tools_FOUND OR NOT Qt6ToolsTools_FOUND)

+        message(STATUS "Qt6Tools or Qt6ToolsTools not found, not generating API documentation")

+        return()

+    endif()

     if (NOT TARGET ${target})

         message(FATAL_ERROR "${target} is not a target")