Update mjson to 1.2.7 (#3807)

packages/m/mjson/xmake.lua

@@ -6,6 +6,7 @@ package("mjson")
 
     add_urls("https://github.com/cesanta/mjson/archive/refs/tags/$(version).zip",
              "https://github.com/cesanta/mjson.git")
+    add_versions("1.2.7", "ab3dfb813c8944f4a8ef6b17b0c2255136937d9fb24ef000e75aedd1fd17248d")
     add_versions("1.2.6", "d801348c38c883802a540eec0b3ea14318837084cbdd32bd83041d03a8850fe6")
 
     add_configs("shared", {description = "Build shared library.", default = false, type = "boolean", readonly = true})