Update github-actions.md

Author: lukfor

docs/tutorials/github-actions.md

@@ -1,5 +1,9 @@
 # Setup nf-test on GitHub Actions
 
+!!! warning
+
+    This feature is experimental and requires nf-test 0.9.0-rc1 or higher
+
 In this tutorial, we will guide you through setting up and running `nf-test` on GitHub Actions. We will start with a simple example where all tests run in a single job, then extend it to demonstrate how you can use sharding to distribute tests across multiple jobs for improved efficiency. Finally, we will show you how to run only the tests affected by the changed files using the `--changes-since` option.
 
 By the end of this tutorial, you will have a clear understanding of how to:
@@ -174,4 +178,4 @@ This configuration ensures that critical changes always result in a comprehensiv
 2. **With Sharding**: Distributes tests across multiple jobs, allowing them to run in parallel.
 3. **With Sharding and Changed Files**: Optimizes the CI process by running only the tests affected by the changed files since the last commit, in parallel jobs.
 
-Choose the configuration that best suits your project's needs. Start with the simpler setup and extend it as needed to improve efficiency and reduce test execution time.
+Choose the configuration that best suits your project's needs. Start with the simpler setup and extend it as needed to improve efficiency and reduce test execution time.