Add tests for the clone panel (#322540)

What does this MR do?

It adds tests for the clone panel. Related context: #322540

How to setup and validate locally (strongly suggested)

1. Install GitLab Development Kit
2. Run individual tests

   bundle exec yarn jest spec/frontend/clone_panel_spec.js
   bundle exec rspec spec/views/shared/_clone_panel.html.haml_spec.rb
   bundle exec rspec spec/views/projects/buttons/_clone.html.haml_spec.rb

3. See that all tests have been passed.

Does this MR meet the acceptance criteria?

Conformity

• I have included changelog trailers, or none are needed. (Does this MR need a changelog?)
• I have added/updated documentation, or it's not needed. (Is documentation required?)
• I have properly separated EE content from FOSS, or this MR is FOSS only. (Where should EE code go?)
• I have added information for database reviewers in the MR description, or it's not needed. (Does this MR have database related changes?)
• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.
• This change is backwards compatible across updates, or this does not apply.

Availability and Testing

• I have added/updated tests following the Testing Guide, or it's not needed. (Consider all test levels. See the Test Planning Process.)
• I have tested this MR in all supported browsers, or it's not needed.
• I have informed the Infrastructure department of a default or new setting change per definition of done, or it's not needed.