cmake: Remove a bunch of unnecessary code

We are no longer C++, we no longer support xcode

Note: This will remove a warning "DO NOT EDIT" comment from __fish_build_paths.fish, but
that's unnecessary. The file is typically in /usr or another
package-manager-owned location, so people don't typically edit it.

And if it did we don't actually *care*, it'll work fine.

cmake/gettext.cmake

@@ -4,21 +4,7 @@ include(FeatureSummary)
 
 option(WITH_GETTEXT "translate messages if gettext is available" ON)
 if(WITH_GETTEXT)
-  if(APPLE)
-    # Fix for https://github.com/fish-shell/fish-shell/issues/5244
-    # via https://gitlab.kitware.com/cmake/cmake/-/issues/18921
-    set(CMAKE_FIND_FRAMEWORK_OLD ${CMAKE_FIND_FRAMEWORK})
-    set(CMAKE_FIND_FRAMEWORK NEVER)
-  endif()
-  find_package(Intl QUIET)
   find_package(Gettext)
-  if(GETTEXT_FOUND)
-      include_directories(${Intl_INCLUDE_DIR})
-  endif()
-  if(APPLE)
-    set(CMAKE_FIND_FRAMEWORK ${CMAKE_FIND_FRAMEWORK_OLD})
-    unset(CMAKE_FIND_FRAMEWORK_OLD)
-  endif()
 endif()
 add_feature_info(gettext GETTEXT_FOUND "translate messages with gettext")
 
@@ -34,12 +20,3 @@ if(GETTEXT_FOUND)
   endforeach()
   set(CMAKE_FOLDER)
 endif()
-
-include(CMakePushCheckState)
-cmake_push_check_state()
-set(CMAKE_REQUIRED_INCLUDES ${CMAKE_REQUIRED_INCLUDES} ${Intl_INCLUDE_DIR})
-set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} ${Intl_LIBRARIES})
-# libintl.h can be compiled into the stdlib on some GLibC systems
-if(Intl_FOUND AND Intl_LIBRARIES)
-  set(LIBINTL_INCLUDE "#include <libintl.h>")
-endif()