revert libpng cmake deps

packages/l/libpng/xmake.lua

@@ -13,7 +13,7 @@ package("libpng")
 
     add_deps("zlib")
     if is_plat("windows", "mingw") then
-        add_deps("cmake >=3.13")
+        add_deps("cmake")
     end
 
     on_install("windows", "mingw", function (package)