Bump rdoc from 6.7.0 to 6.12.0 in /ruby

Bumps [rdoc](https://github.com/ruby/rdoc) from 6.7.0 to 6.12.0.
- [Release notes](https://github.com/ruby/rdoc/releases)
- [Changelog](https://github.com/ruby/rdoc/blob/master/History.rdoc)
- [Commits](ruby/rdoc@v6.7.0...v6.12.0)

---
updated-dependencies:
- dependency-name: rdoc
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

ruby/Gemfile

@@ -7,7 +7,7 @@ gemspec
 
 gem "rake", "~> 13.2"
 
-gem "rdoc", "~> 6.7"
+gem "rdoc", "~> 6.12"
 
 gem "rspec", "~> 3.13"
 

ruby/Gemfile.lock

@@ -7,19 +7,21 @@ GEM
   remote: https://rubygems.org/
   specs:
     ast (2.4.2)
+    date (3.4.1)
     diff-lcs (1.5.1)
     json (2.8.2)
     language_server-protocol (3.17.0.3)
     parallel (1.26.3)
     parser (3.3.6.0)
       ast (~> 2.4.1)
       racc
-    psych (5.1.2)
+    psych (5.2.3)
+      date
       stringio
     racc (1.8.1)
     rainbow (3.1.1)
     rake (13.2.1)
-    rdoc (6.7.0)
+    rdoc (6.12.0)
       psych (>= 4.0.0)
     regexp_parser (2.9.3)
     rspec (3.13.0)
@@ -48,7 +50,7 @@ GEM
     rubocop-ast (1.36.2)
       parser (>= 3.3.1.0)
     ruby-progressbar (1.13.0)
-    stringio (3.1.1)
+    stringio (3.1.2)
     unicode-display_width (3.1.2)
       unicode-emoji (~> 4.0, >= 4.0.4)
     unicode-emoji (4.0.4)
@@ -60,7 +62,7 @@ PLATFORMS
 DEPENDENCIES
   collatz!
   rake (~> 13.2)
-  rdoc (~> 6.7)
+  rdoc (~> 6.12)
   rspec (~> 3.13)
   rubocop (~> 1.69)