build(deps-dev): update rdoc requirement from 7.0.3 to 7.2.0 (#684)

Updates the requirements on [rdoc](https://github.com/ruby/rdoc) to permit the latest version.
- [Release notes](https://github.com/ruby/rdoc/releases)
- [Changelog](https://github.com/ruby/rdoc/blob/master/History.rdoc)
- [Commits](ruby/rdoc@v7.0.3...v7.2.0)

---
updated-dependencies:
- dependency-name: rdoc
  dependency-version: 7.2.0
  dependency-type: direct:development
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Gemfile

@@ -12,7 +12,7 @@ group :test do
 end
 
 group :development do
-  gem "rdoc", "7.0.3"
+  gem "rdoc", "7.2.0"
 
   gem "rubocop", "1.59.0", require: false
   gem "rubocop-minitest", "0.34.5", require: false