build(deps): bump @bull-board/express from 5.20.5 to 5.21.0

Bumps [@bull-board/express](https://github.com/felixmosh/bull-board/tree/HEAD/packages/express) from 5.20.5 to 5.21.0.
- [Release notes](https://github.com/felixmosh/bull-board/releases)
- [Changelog](https://github.com/felixmosh/bull-board/blob/master/CHANGELOG.md)
- [Commits](https://github.com/felixmosh/bull-board/commits/v5.21.0/packages/express)

---
updated-dependencies:
- dependency-name: "@bull-board/express"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

package.json

@@ -17,7 +17,7 @@
   "dependencies": {
     "@aws-sdk/client-sns": "^3.609.0",
     "@bull-board/api": "^5.20.5",
-    "@bull-board/express": "^5.20.5",
+    "@bull-board/express": "^5.21.0",
     "@polkadot/api": "^12.0.1",
     "@polkadot/keyring": "^12.6.2",
     "@polkadot/types": "^12.0.1",