Fix junit result merging

What does this MR do?

CI for some reason doesn't like extended glob syntax and is raising an error: https://ops.gitlab.net/gitlab-org/quality/staging-canary/-/jobs/14238814#L1942

Turns out we don't really need it, simple output of ls will have the correct order of files and results should be merged correctly.

Check-list

• Ensure commits include Changelog: trailer
• Verify the change in all affected pipelines.