Bump rdoc from 6.3.3 to 6.3.4.1

Bumps [rdoc](https://github.com/ruby/rdoc) from 6.3.3 to 6.3.4.1.
- [Release notes](https://github.com/ruby/rdoc/releases)
- [Changelog](https://github.com/ruby/rdoc/blob/master/History.rdoc)
- [Commits](ruby/rdoc@v6.3.3...v6.3.4.1)

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

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

Author: dependabot[bot]

Gemfile.lock

@@ -75,7 +75,7 @@ GEM
     rainbow (3.1.1)
     rake (13.0.1)
     rchardet (1.8.0)
-    rdoc (6.3.3)
+    rdoc (6.3.4.1)
     regexp_parser (2.6.1)
     reline (0.3.3)
       io-console (~> 0.5)