Bump opentelemetry-instrumentation-ethon from 0.21.8 to 0.21.9

Bumps [opentelemetry-instrumentation-ethon](https://github.com/open-telemetry/opentelemetry-ruby-contrib) from 0.21.8 to 0.21.9.
- [Release notes](https://github.com/open-telemetry/opentelemetry-ruby-contrib/releases)
- [Changelog](https://github.com/open-telemetry/opentelemetry-ruby-contrib/blob/main/instrumentation/ethon/CHANGELOG.md)
- [Commits](open-telemetry/opentelemetry-ruby-contrib@opentelemetry-instrumentation-ethon/v0.21.8...opentelemetry-instrumentation-ethon/v0.21.9)

---
updated-dependencies:
- dependency-name: opentelemetry-instrumentation-ethon
  dependency-type: indirect
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -285,7 +285,7 @@ GEM
     opentelemetry-instrumentation-delayed_job (0.22.4)
       opentelemetry-api (~> 1.0)
       opentelemetry-instrumentation-base (~> 0.22.1)
-    opentelemetry-instrumentation-ethon (0.21.8)
+    opentelemetry-instrumentation-ethon (0.21.9)
       opentelemetry-api (~> 1.0)
       opentelemetry-instrumentation-base (~> 0.22.1)
     opentelemetry-instrumentation-excon (0.22.4)