Update webextension-polyfill to work in the most recent Chrome version

manifest.json

@@ -1,6 +1,6 @@
 {
   "name": "Three.js Developer Tools",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "description": "Developer tools for 3D library three.js.",
   "devtools_page": "src/extension/devtools.html",
   "background": {
@@ -37,4 +37,4 @@
       "id": "[email protected]"
     }
   }
-}
+}

package.json

@@ -1,7 +1,7 @@
 {
   "name": "three-devtools",
   "private": true,
-  "version": "0.4.0",
+  "version": "0.4.1",
   "description": "three.js developer tools web extension",
   "scripts": {
     "build:source": "./scripts/build-source.sh",
@@ -27,7 +27,7 @@
     "lit-element": "2.2.1",
     "lit-html": "1.1.2",
     "three": "0.137.0",
-    "webextension-polyfill": "0.4.0"
+    "webextension-polyfill": "^0.9.0"
   },
   "devDependencies": {
     "http-server": "^0.12.0",