Add extsources to entt (#1340)

packages/e/entt/xmake.lua

@@ -16,6 +16,10 @@ package("entt")
     add_versions("v3.6.0", "94b7dc874acd0961cfc28cf6b0342eeb0b7c58250ddde8bdc6c101e84b74c190")
 
     add_deps("cmake")
+    
+    if is_plat("mingw") and is_subhost("msys") then
+        add_extsources("pacman::entt")
+    end
 
     on_install(function (package)
         local configs = {"-DENTT_BUILD_TESTING=OFF"}