Remove not released status from documentation

What does this MR do?

remove the not released yet status

Are there points in the code the reviewer needs to double check?

no

Why was this MR needed?

the documentation is outdated

What are the relevant issue numbers?

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Documentation created/updated

doc/ci/yaml/README.md

@@ -133,7 +133,7 @@ builds, including deploy builds. This can be an array or a multi-line string.
 ### after_script
 >**Note:**
-Introduced in GitLab 8.7 and requires Gitlab Runner v1.2 (not yet released)
+Introduced in GitLab 8.7 and requires Gitlab Runner v1.2
 `after_script` is used to define the command that will be run after for all
 builds. This has to be an array or a multi-line string.