Disabled the MSVC compile-time optimizations for CI

CMakeLists.txt

@@ -230,10 +230,15 @@ if (WIN32)
             # we don't need them on CI.
             string(REPLACE "/INCREMENTAL" "/INCREMENTAL:NO" ${LinkerFlag} ${${LinkerFlag}})
         endforeach()
+
+        # We turn off compile-time optimizations for CI, as options that speed up the compile-time
+        # (e.g. /MP) might increase memory usage, leading to instabilities on limited CI machines.
+        option(FILAMENT_SHORTEN_MSVC_COMPILATION "Shorten compile-time in Visual Studio" OFF)
+    else()
+        option(FILAMENT_SHORTEN_MSVC_COMPILATION "Shorten compile-time in Visual Studio" ON)
     endif()
 
     if (MSVC)
-        option(FILAMENT_SHORTEN_MSVC_COMPILATION "Shorten compile-time in Visual Studio" ON)
         if (FILAMENT_SHORTEN_MSVC_COMPILATION)
             # enable multi-processor compilation
             set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /MP")