Bump acorn from 8.3.0 to 8.4.0

Bumps [acorn](https://github.com/acornjs/acorn) from 8.3.0 to 8.4.0.
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](acornjs/acorn@8.3.0...8.4.0)

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

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

package.json

@@ -30,7 +30,7 @@
 		"@babel/core": "^7.14.5",
 		"@babel/preset-env": "^7.14.4",
 		"@nextcloud/webpack-vue-config": "^1.2.0",
-		"acorn": "^8.3.0",
+		"acorn": "^8.4.0",
 		"babel-eslint": "^10.1.0",
 		"babel-loader": "^8.2.2",
 		"css-loader": "^3.6.0",