Convert CI YAML variables keys into strings

So that this would be more consistent with the other variables,
which all of them are string based.

Closes #25554

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/ci/gitlab_ci_yaml_processor.rb b/lib/ci/gitlab_ci_yaml_processor.rb
index fef652cb975..8806a506ffa 100644
--- a/lib/ci/gitlab_ci_yaml_processor.rb
+++ b/lib/ci/gitlab_ci_yaml_processor.rb
@@ -118,7 +118,7 @@ module Ci
         .merge(job_variables(name))
 
       variables.map do |key, value|
-        { key: key, value: value, public: true }
+        { key: key.to_s, value: value.to_s, public: true }
       end
     end