Bump ffi-yajl from 2.4.0 to 2.6.0 in /src/chef-server-ctl

Bumps [ffi-yajl](https://github.com/chef/ffi-yajl) from 2.4.0 to 2.6.0.
- [Changelog](https://github.com/chef/ffi-yajl/blob/main/CHANGELOG.md)
- [Commits](https://github.com/chef/ffi-yajl/commits/2.6.0)

---
updated-dependencies:
- dependency-name: ffi-yajl
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

src/chef-server-ctl/Gemfile.lock

@@ -149,7 +149,7 @@ GEM
     ffi (1.15.5)
     ffi-libarchive (1.1.3)
       ffi (~> 1.0)
-    ffi-yajl (2.4.0)
+    ffi-yajl (2.6.0)
       libyajl2 (>= 1.2)
     fuzzyurl (0.9.0)
     gssapi (1.3.1)