Bump nokogiri from 1.16.7 to 1.18.8 in /examples/simple_rails_api

Bumps [nokogiri](https://github.com/sparklemotion/nokogiri) from 1.16.7 to 1.18.8.
- [Release notes](https://github.com/sparklemotion/nokogiri/releases)
- [Changelog](https://github.com/sparklemotion/nokogiri/blob/main/CHANGELOG.md)
- [Commits](sparklemotion/nokogiri@v1.16.7...v1.18.8)

---
updated-dependencies:
- dependency-name: nokogiri
  dependency-version: 1.18.8
  dependency-type: indirect
...

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

Author: dependabot[bot]

examples/simple_rails_api/Gemfile.lock

@@ -87,7 +87,7 @@ GEM
     marcel (1.0.4)
     method_source (1.1.0)
     mini_mime (1.1.5)
-    mini_portile2 (2.8.7)
+    mini_portile2 (2.8.8)
     minitest (5.25.1)
     msgpack (1.4.2)
     net-imap (0.4.16)
@@ -100,7 +100,7 @@ GEM
     net-smtp (0.5.0)
       net-protocol
     nio4r (2.7.3)
-    nokogiri (1.16.7)
+    nokogiri (1.18.8)
       mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
     puma (5.6.9)