Bump webextension-polyfill from 0.8.0 to 0.9.0 (#24)

* Bump webextension-polyfill from 0.8.0 to 0.9.0

Bumps [webextension-polyfill](https://github.com/mozilla/webextension-polyfill) from 0.8.0 to 0.9.0.
- [Release notes](https://github.com/mozilla/webextension-polyfill/releases)
- [Commits](mozilla/webextension-polyfill@0.8.0...0.9.0)

---
updated-dependencies:
- dependency-name: webextension-polyfill
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

* update browser-polyfill.min.js

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: April Sylph <28949509+AprilSylph@users.noreply.github.com>

package.json

@@ -20,7 +20,7 @@
   },
   "dependencies": {
     "normalize.css": "^8.0.1",
-    "webextension-polyfill": "^0.8.0"
+    "webextension-polyfill": "^0.9.0"
   },
   "webExt": {
     "sourceDir": "src/",