Use project name only for container images in QA tests

What does this MR do and why?

Closes #381409 (closed)

Container is not showing the full path anymore due to !91548 (merged) / !101897 (merged)

Previously the test was searching for the full project path.

Example of failures: https://gitlab.com/gitlab-org/gitlab/-/jobs/3266878728

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.

qa/qa/specs/features/browser_ui/5_package/container_registry/container_registry_omnibus_spec.rb

@@ -174,7 +174,7 @@ module QA
             Page::Project::Registry::Show.perform do |registry|
               expect(registry).to have_registry_repository(project.name)
 
-              registry.click_on_image(project.path_with_namespace)
+              registry.click_on_image(project.name)
               expect(registry).to have_tag('master')
             end
           end
@@ -232,7 +232,7 @@ module QA
           Page::Project::Registry::Show.perform do |registry|
             expect(registry).to have_registry_repository(project.name)
 
-            registry.click_on_image(project.path_with_namespace)
+            registry.click_on_image(project.name)
 
             expect(registry).to have_tag('master')