chore: remove IE11 from main browserlist declaration

This was missed in the ES6 switcheroo

We then will also add IE11 for a specific bundle here https://github.com/PostHog/posthog-js/blob/4ac2e5dcaed08240b7ecddc5310aefed0ab9660a/rollup.config.js#L25-L28

package.json

@@ -122,7 +122,7 @@
         ]
     },
     "browserslist": [
-        "> 0.5%, last 2 versions, Firefox ESR, not dead, IE 11"
+        "> 0.5%, last 2 versions, Firefox ESR, not dead"
     ],
     "pnpm": {
         "patchedDependencies": {