Build(deps): Bump webpack from 5.83.1 to 5.84.0 in /app/assets/javascripts (#21732)

Bumps [webpack](https://github.com/webpack/webpack) from 5.83.1 to 5.84.0.
- [Release notes](https://github.com/webpack/webpack/releases)
- [Commits](https://github.com/webpack/webpack/compare/v5.83.1...v5.84.0)

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

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

app/assets/javascripts/discourse-plugins/package.json

@@ -14,7 +14,7 @@
     "ember-cli": "~4.12.0",
     "ember-cli-babel": "^7.26.11",
     "ember-cli-htmlbars": "^6.2.0",
-    "webpack": "^5.83.1"
+    "webpack": "^5.84.0"
   },
   "devDependencies": {
     "@babel/core": "^7.21.8"