[Dependency] Bump erb from 6.0.3 to 6.0.4

Bumps [erb](https://github.com/ruby/erb) from 6.0.3 to 6.0.4.
- [Release notes](https://github.com/ruby/erb/releases)
- [Changelog](https://github.com/ruby/erb/blob/master/NEWS.md)
- [Commits](ruby/erb@v6.0.3...v6.0.4)

---
updated-dependencies:
- dependency-name: erb
  dependency-version: 6.0.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

Gemfile.lock

@@ -30,7 +30,7 @@ GEM
     em-websocket (0.5.3)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0)
-    erb (6.0.3)
+    erb (6.0.4)
     ethon (0.16.0)
       ffi (>= 1.15.0)
     eventmachine (1.2.7)