Update EnTT to 3.8.1 (#552)

* Update EnTT to 3.8.1

* Restore v3.8.0

packages/e/entt/xmake.lua

@@ -6,6 +6,7 @@ package("entt")
 
     set_urls("https://github.com/skypjack/entt/archive/$(version).tar.gz",
              "https://github.com/skypjack/entt.git")
+    add_versions("v3.8.1", "a2b767f06bca67a73a4d71fb9ebb6ed823bb5146faad3c282b9dbbbdae1aa01b")
     add_versions("v3.8.0", "71c8ff5a604e8e214571a8b2218dfeaf61be59e2fe2ff5b550b4810c37d4da3c")
     add_versions("v3.7.1", "fe3ce773c17797c0c57ffa97f73902854fcc8e7afc7e09bea373e0c64fa24a23")
     add_versions("v3.7.0", "39ad5c42acf3434f8c37e0baa18a8cb562c0845383a6b4da17fdbacc9f0a7695")