Bump web-ext from 7.8.0 to 7.9.0 (#10)

Bumps [web-ext](https://github.com/mozilla/web-ext) from 7.8.0 to 7.9.0.
- [Release notes](https://github.com/mozilla/web-ext/releases)
- [Commits](https://github.com/mozilla/web-ext/compare/7.8.0...7.9.0)

---
updated-dependencies:
- dependency-name: web-ext
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

package.json

@@ -1,6 +1,6 @@
 {
   "devDependencies": {
-    "web-ext": "^7.8.0"
+    "web-ext": "^7.9.0"
   },
   "scripts": {
     "start:firefox": "web-ext run --source-dir .",