Update links to hidden variables
Problem/Motivation
In #3343522: Hide variables that should not be overridden, the variables that should not be overridden by individual projects/pipelines were moved to the include.drupalci.hidden-variables.yml file. However, the descriptions of the three variables that use semantic labels (which are now defined in hidden-variables.yml) still reference the old file.
Steps to reproduce
Run a custom pipeline and try to find the semantic labels by following the displayed link.
Proposed resolution
Fix the referenced URL.
Remaining tasks
- Review and merge the MR.
Edited by drupalbot