CMake: Fix build with wxBUILD_MONOLITHIC

Add wxUSE_WEBVIEW test before using wx_webview_copy_webview2_loader.

Closes #22315, #22316.

build/cmake/lib/CMakeLists.txt

@@ -96,8 +96,10 @@ if(wxBUILD_MONOLITHIC)
     foreach(dep ${wxMONO_DEPENDENCIES})
         add_dependencies(wxmono ${dep})
     endforeach()
+    if(wxUSE_WEBVIEW)
         wx_webview_copy_webview2_loader(wxmono)
     endif()
+endif()
 
 # Propagate variable(s) to parent scope
 set(wxLIB_TARGETS ${wxLIB_TARGETS} PARENT_SCOPE)