robotstxt: remove limits (#4941)

packages/r/robotstxt/xmake.lua

@@ -9,7 +9,7 @@ package("robotstxt")
 
     add_deps("abseil")
 
-    on_install("macosx", "linux", "windows", function (package)
+    on_install(function (package)
         io.writefile("xmake.lua", [[
             add_rules("mode.debug", "mode.release")
             add_requires("abseil")