HPCC-25883 Workaround for cmake compiler version issue

Signed-off-by: Jake Smith <jake.smith@lexisnexisrisk.com>

CMakeLists.txt

@@ -69,6 +69,11 @@
 
 project(hpccsystems-platform)
 
+# Stupid workaround. See https://gitlab.kitware.com/cmake/cmake/-/issues/21378
+# If cmake runs twice, cmake might not correctly set the compiler version variables
+unset ( ENV{CC} )
+unset ( ENV{CXX} )
+
 cmake_minimum_required(VERSION 3.13.0)
 
 set(TOP_LEVEL_PROJECT ON)