BUGFIX: Make web-ext-types a peer dependency

Author: brizental

glean/package.json

@@ -91,5 +91,8 @@
   },
   "dependencies": {
     "uuid": "^8.3.2"
+  },
+  "peerDependencies": {
+    "web-ext-types": "^3.2.1"
   }
 }