Rework patch to OpenSfM build config to still support VS 16 (v142 toolset).

SuperBuild/cmake/External-OpenSfM.cmake

@@ -5,7 +5,13 @@ ProcessorCount(nproc)
 
 set(EXTRA_INCLUDE_DIRS "")
 if(WIN32)
-  set(OpenCV_DIR "${SB_INSTALL_DIR}/x64/vc17/lib")
+  if (MSVC_TOOLSET_VERSION EQUAL 143)
+    set(OpenCV_DIR "${SB_INSTALL_DIR}/x64/vc17/lib")
+  elseif(MSVC_TOOLSET_VERSION EQUAL 142)
+    set(OpenCV_DIR "${SB_INSTALL_DIR}/x64/vc16/lib")
+  else()
+    message(FATAL_ERROR "Unsupported MSVC toolset version detected: ${MSVC_TOOLSET_VERSION}")
+  endif()
   set(BUILD_CMD ${CMAKE_COMMAND} --build "${SB_BUILD_DIR}/opensfm" --config "${CMAKE_BUILD_TYPE}")
 else()
   set(BUILD_CMD make "-j${nproc}")