IAR: Restore support for projects not enabling policy CMP0057

Since commit 5b9bfe738c (IAR: Moved search logic to BinUtils.,
2021-07-19, v3.21.1~14^2), we use the `IN_LIST` operator in the
`CMakeFindBinUtils` module.  Set policy `CMP0057` to ensure it is
available regardless of the project's policy settings.

Fixes: #22640

Modules/CMakeFindBinUtils.cmake

@@ -20,6 +20,9 @@
 
 # on UNIX, cygwin and mingw
 
+cmake_policy(PUSH)
+cmake_policy(SET CMP0057 NEW) # if IN_LIST
+
 # Resolve full path of CMAKE_TOOL from user-defined name and SEARCH_PATH.
 function(__resolve_tool_path CMAKE_TOOL SEARCH_PATH DOCSTRING)
 
@@ -240,3 +243,5 @@ if("x${CMAKE_${_CMAKE_PROCESSING_LANGUAGE}_COMPILER_ID}" MATCHES "^xIAR$")
   set(CMAKE_IAR_LINKER "${CMAKE_LINKER}" CACHE FILEPATH "The IAR ILINK linker")
   mark_as_advanced(CMAKE_IAR_LINKER CMAKE_IAR_AR)
 endif()
+
+cmake_policy(POP)