build(deps): bump msgpack from 1.8.0 to 1.8.1 (cloudfoundry#5135)

Bumps [msgpack](https://github.com/msgpack/msgpack-ruby) from 1.8.0 to 1.8.1.
- [Changelog](https://github.com/msgpack/msgpack-ruby/blob/master/ChangeLog)
- [Commits](msgpack/msgpack-ruby@v1.8.0...v1.8.1)

---
updated-dependencies:
- dependency-name: msgpack
  dependency-version: 1.8.1
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

Gemfile.lock

@@ -308,7 +308,7 @@ GEM
       faraday (~> 0.9)
       faraday-cookie_jar (~> 0.0.6)
       ms_rest (~> 0.6.3)
-    msgpack (1.8.0)
+    msgpack (1.8.1)
     multi_json (1.21.1)
     multipart-parser (0.1.1)
     multipart-post (2.4.1)