workflows: bump ruby/setup-ruby from 1.205.0 to 1.206.0

Bumps [ruby/setup-ruby](https://github.com/ruby/setup-ruby) from 1.205.0 to 1.206.0.
- [Release notes](https://github.com/ruby/setup-ruby/releases)
- [Changelog](https://github.com/ruby/setup-ruby/blob/master/release.rb)
- [Commits](ruby/setup-ruby@540484a...bfefad8)

---
updated-dependencies:
- dependency-name: ruby/setup-ruby
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/workflows/main.yml

@@ -22,7 +22,7 @@ jobs:
         persist-credentials: false
 
     - name: Set up Ruby
-      uses: ruby/setup-ruby@540484a3c0f308b08619664ec40bf6c371d172c3 # v1.205.0
+      uses: ruby/setup-ruby@bfefad842bb982ff05b233bcbc1571d97a87e69f # v1.206.0
       with:
         bundler-cache: true