Update fmt to 8.0.0 (#461)

* Update fmt to 8.0.0

* Update xmake.lua

packages/f/fmt/xmake.lua

@@ -4,6 +4,7 @@ package("fmt")
     set_description("fmt is an open-source formatting library for C++. It can be used as a safe and fast alternative to (s)printf and iostreams.")
 
     set_urls("https://github.com/fmtlib/fmt/releases/download/$(version)/fmt-$(version).zip")
+    add_versions("8.0.0", "36016a75dd6e0a9c1c7df5edb98c93a3e77dabcf122de364116efb9f23c6954a")
     add_versions("7.1.3", "5d98c504d0205f912e22449ecdea776b78ce0bb096927334f80781e720084c9f")
     add_versions("6.2.0", "a4468d528682143dcef2f16068104e03ef50467b0170b6125c9caf777d27bf10")
     add_versions("6.0.0", "b4a16b38fa171f15dbfb958b02da9bbef2c482debadf64ac81ec61b5ac422440")