chore(deps): bump nokogiri in /images/fluentd/outputs

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.16.6 to 1.18.3.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/v1.18.3/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.16.6...v1.18.3)

---
updated-dependencies:
- dependency-name: nokogiri
  dependency-type: indirect
...

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

Author: dependabot[bot]

images/fluentd/outputs/Gemfile.lock

@@ -282,7 +282,7 @@ GEM
     net-smtp (0.4.0)
       net-protocol
     netrc (0.11.0)
-    nokogiri (1.16.6)
+    nokogiri (1.18.3)
       mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
     openid_connect (1.1.8)
@@ -301,7 +301,7 @@ GEM
     os (1.1.4)
     prometheus-client (4.2.1)
     public_suffix (5.0.3)
-    racc (1.8.0)
+    racc (1.8.1)
     rack (3.0.12)
     rack-oauth2 (1.21.3)
       activesupport