cmake: fix model_build_helper.pyi on windows (#4512)

cmake/python.cmake

@@ -550,8 +550,9 @@ add_custom_command(
     ${PYTHON_PROJECT}/.libs
 
   COMMAND ${CMAKE_COMMAND} -E
-    $<IF:${need_unix_re2_lib},copy,true>
+    $<IF:$<BOOL:${BUILD_re2}>,copy,true>
     $<${need_unix_re2_lib}:$<TARGET_SONAME_FILE:re2::re2>>
+    $<${need_windows_re2_lib}:$<TARGET_FILE:re2::re2>>
     ${PYTHON_PROJECT}/.libs
 
   COMMAND ${CMAKE_COMMAND} -E

ortools/python/__init__.py.in

@@ -55,7 +55,7 @@ def _load_ortools_libs():
         except:
             pass
         else:
-            for dll in ["zlib1.dll", "abseil_dll.dll", "utf8_validity.dll", "libprotobuf.dll", "highs.dll"]:
+            for dll in ["zlib1.dll", "abseil_dll.dll", "utf8_validity.dll", "re2.dll", "libprotobuf.dll", "highs.dll"]:
               dll_path = os.path.join(basedir, ".libs", dll)
               if os.path.exists(dll_path):
                   print(f"load {dll_path}...")