cmake: revert cmake support for 10.4 Tiger

This is a reversed patch of https://gitlab.kitware.com/cmake/cmake/-/merge_requests/6426.

_CURRENT_OSX_VERSION isn't set properly, which causes this condition to fail,
which means we don't get CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG which means
we can't compile libcxx. Ugh.

pkgs/development/tools/build-managers/cmake/darwin-always-set-runtime-c-flag.patch

@@ -0,0 +1,14 @@
+Revert of commit 1af23c4de2c7d58c06171d70b37794b5c860d5f4.
+--- b/Modules/Platform/Darwin.cmake
++++ a/Modules/Platform/Darwin.cmake
+@@ -47,9 +47,7 @@
+ set(CMAKE_SHARED_MODULE_SUFFIX ".so")
+ set(CMAKE_MODULE_EXISTS 1)
+ set(CMAKE_DL_LIBS "")
++set(CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG "-Wl,-rpath,")
+-if(NOT "${_CURRENT_OSX_VERSION}" VERSION_LESS "10.5")
+-  set(CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG "-Wl,-rpath,")
+-endif()
+ 
+ foreach(lang C CXX OBJC OBJCXX)
+   set(CMAKE_${lang}_OSX_COMPATIBILITY_VERSION_FLAG "-compatibility_version ")

pkgs/development/tools/build-managers/cmake/default.nix

@@ -36,7 +36,9 @@ stdenv.mkDerivation rec {
 
   ] ++ lib.optional stdenv.isCygwin ./3.2.2-cygwin.patch
   # Derived from https://github.com/curl/curl/commit/31f631a142d855f069242f3e0c643beec25d1b51
-  ++ lib.optional (stdenv.isDarwin && isBootstrap) ./remove-systemconfiguration-dep.patch;
+  ++ lib.optional (stdenv.isDarwin && isBootstrap) ./remove-systemconfiguration-dep.patch
+  # On Darwin, always set CMAKE_SHARED_LIBRARY_RUNTIME_C_FLAG.
+  ++ lib.optional stdenv.isDarwin ./darwin-always-set-runtime-c-flag.patch;
 
   outputs = [ "out" ]
     ++ lib.optionals buildDocs [ "man" "info" ];