[FIX] package.json: remove browser value

As far as I can tell, the browser value overrides the main value in many
cases.  But then, we don't want to use the iife format, since it don't
work well with bundlers. This commit fixes the issue by simply removing
the key, so the main entry will be used instead.

maybe fixes #1181

package.json

@@ -3,7 +3,6 @@
   "version": "2.0.0-beta-14",
   "description": "Odoo Web Library (OWL)",
   "main": "dist/owl.cjs.js",
-  "browser": "dist/owl.iife.js",
   "module": "dist/owl.es.js",
   "types": "dist/types/owl.d.ts",
   "files": [