CMake: Remove debug list source files comparison

This was needed in the early days of the CMake port when the list of
source files would change due to being added to the qmake project
files.

Change-Id: I7afd219b24ab7a0d87fce26ba35dac75cf8caa5b
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

cmake/QtCreatorAPI.cmake

@@ -169,8 +169,6 @@ function(add_qtc_library name)
     set(_arg_SOURCES ${prefixed_sources})
   endif()
 
-  compare_sources_with_existing_disk_files(${name} "${_arg_SOURCES}")
-
   set(library_type SHARED)
   if (_arg_STATIC)
     set(library_type STATIC)
@@ -316,7 +314,7 @@ endfunction(add_qtc_library)
 
 function(add_qtc_plugin target_name)
   cmake_parse_arguments(_arg
-    "SKIP_DEBUG_CMAKE_FILE_CHECK;SKIP_INSTALL;INTERNAL_ONLY;SKIP_TRANSLATION;EXPORT;SKIP_PCH"
+    "SKIP_INSTALL;INTERNAL_ONLY;SKIP_TRANSLATION;EXPORT;SKIP_PCH"
     "VERSION;COMPAT_VERSION;PLUGIN_JSON_IN;PLUGIN_PATH;PLUGIN_NAME;OUTPUT_NAME;BUILD_DEFAULT"
     "CONDITION;DEPENDS;PUBLIC_DEPENDS;DEFINES;PUBLIC_DEFINES;INCLUDES;PUBLIC_INCLUDES;SOURCES;EXPLICIT_MOC;SKIP_AUTOMOC;EXTRA_TRANSLATIONS;PLUGIN_DEPENDS;PLUGIN_RECOMMENDS;PLUGIN_TEST_DEPENDS;PROPERTIES"
     ${ARGN}
@@ -374,10 +372,6 @@ function(add_qtc_plugin target_name)
     set(_arg_COMPAT_VERSION ${_arg_VERSION})
   endif()
 
-  if (NOT _arg_SKIP_DEBUG_CMAKE_FILE_CHECK)
-    compare_sources_with_existing_disk_files(${target_name} "${_arg_SOURCES}")
-  endif()
-
   # Generate dependency list:
   find_dependent_plugins(_DEP_PLUGINS ${_arg_PLUGIN_DEPENDS})