build(deps-dev): bump web-ext from 7.6.2 to 7.7.0 in /addon

Bumps [web-ext](https://github.com/mozilla/web-ext) from 7.6.2 to 7.7.0.
- [Release notes](https://github.com/mozilla/web-ext/releases)
- [Commits](mozilla/web-ext@7.6.2...7.7.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]