Bump webrick from 1.8.2 to 1.9.0

Bumps [webrick](https://github.com/ruby/webrick) from 1.8.2 to 1.9.0.
- [Release notes](https://github.com/ruby/webrick/releases)
- [Commits](ruby/webrick@v1.8.2...v1.9.0)

---
updated-dependencies:
- dependency-name: webrick
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Gemfile.lock

@@ -350,7 +350,7 @@ GEM
       addressable (>= 2.8.0)
       crack (>= 0.3.2)
       hashdiff (>= 0.4.0, < 2.0.0)
-    webrick (1.8.2)
+    webrick (1.9.0)
     websocket (1.2.11)
     websocket-driver (0.7.6)
       websocket-extensions (>= 0.1.0)