Bump async from 3.2.5 to 3.2.6 (#6602)

Bumps [async](https://github.com/caolan/async) from 3.2.5 to 3.2.6.
- [Release notes](https://github.com/caolan/async/releases)
- [Changelog](https://github.com/caolan/async/blob/master/CHANGELOG.md)
- [Commits](https://github.com/caolan/async/compare/v3.2.5...v3.2.6)

---
updated-dependencies:
- dependency-name: async
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

src/package.json

@@ -31,7 +31,7 @@
   ],
   "dependencies": {
     "@etherpad/express-session": "^1.18.2",
-    "async": "^3.2.5",
+    "async": "^3.2.6",
     "axios": "^1.7.4",
     "cookie-parser": "^1.4.6",
     "cross-env": "^7.0.3",