⬆️ Bump msgpack from 1.7.2 to 1.7.3 in /builder

Bumps [msgpack](https://github.com/msgpack/msgpack-ruby) from 1.7.2 to 1.7.3.
- [Changelog](https://github.com/msgpack/msgpack-ruby/blob/master/ChangeLog)
- [Commits](msgpack/msgpack-ruby@v1.7.2...v1.7.3)

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

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

builder/Gemfile.lock

@@ -143,7 +143,7 @@ GEM
     mini_magick (4.13.2)
     mini_mime (1.1.5)
     minitest (5.25.1)
-    msgpack (1.7.2)
+    msgpack (1.7.3)
     net-imap (0.4.16)
       date
       net-protocol