refactor: remove global window assignment for Artplayer and template export

- Removed the assignment of Artplayer to the global window object in index.js of the artplayer package.
- Eliminated the window export for the template plugin in index.js, streamlining the code and reducing global scope pollution.

scripts/plugin/template/src/index.js

@@ -24,8 +24,4 @@ if (typeof document !== 'undefined') {
     }
   }
   $style.textContent = style
-}
-
-if (typeof window !== 'undefined') {
-    window.{{export}} = {{export}};
-}
+}