Clarify RSpec support for CI platforms

Author: 3v0k4

docusaurus/docs/ruby/retry-only-failures.md

@@ -22,7 +22,7 @@ This feature is limited to beta-testers: write to [email protected] to req
 
 :::caution
 
-Only RSpec on GitHub Actions, CircleCI, GitLab CI, and Buildkite are supported for now.
+Only RSpec ([Queue Mode](queue-mode.mdx)) on GitHub Actions, CircleCI, GitLab CI, and Buildkite are supported for now.
 
 :::