CPack/WiX: Add option to skip the WixUIExtension

Fixes: #22747

Help/cpack_gen/wix.rst

@@ -320,3 +320,11 @@ Windows using WiX.
  name is the plain namespace without the usual xmlns: prefix and url is an unquoted
  namespace url. A list of commonly known WiX schemata can be found here:
  https://wixtoolset.org/documentation/manual/v3/xsd/
+
+.. variable:: CPACK_WIX_SKIP_WIX_UI_EXTENSION
+
+ .. versionadded:: 3.23
+
+ If this variable is set then the inclusion of WixUIExtensions is skipped,
+ i.e. the ``-ext "WixUIExtension"`` command line is not included during
+ the execution of the WiX light tool.

Help/release/dev/cpack-wix-skip-ui-ext.rst

@@ -0,0 +1,5 @@
+cpack-wix-skip-ui-ext
+---------------------
+
+* An option to the WiX Generator was added to be able to skip
+  the inclusion of the WixUIExtensions

Source/CPack/WiX/cmCPackWIXGenerator.cxx

@@ -219,7 +219,9 @@ bool cmCPackWIXGenerator::InitializeWiXConfiguration()
   CollectExtensions("CPACK_WIX_EXTENSIONS", this->CandleExtensions);
   CollectExtensions("CPACK_WIX_CANDLE_EXTENSIONS", this->CandleExtensions);
 
-  this->LightExtensions.insert("WixUIExtension");
+  if (!cmIsOn(GetOption("CPACK_WIX_SKIP_WIX_UI_EXTENSION"))) {
+    this->LightExtensions.insert("WixUIExtension");
+  }
   CollectExtensions("CPACK_WIX_EXTENSIONS", this->LightExtensions);
   CollectExtensions("CPACK_WIX_LIGHT_EXTENSIONS", this->LightExtensions);
   CollectXmlNamespaces("CPACK_WIX_CUSTOM_XMLNS", this->CustomXmlNamespaces);