Improve comment on CMP0115

Co-authored-by: Kamil Śliwak <[email protected]>

Author: Pospelove

cmake/EthPolicy.cmake

@@ -27,7 +27,8 @@ macro (eth_policy)
 	endif()
 
 	if(POLICY CMP0115)
-		# speedup of cmake command on Windows
+		# Require explicit extensions for source files, do not guess.
+		# The extra calls to GetFileAttributesW significantly slow down cmake on Windows.
 		# https://gitlab.kitware.com/cmake/cmake/-/issues/23154
 		cmake_policy(SET CMP0115 NEW)
 	endif()