Migrate sidebar_date_picker_spec to Jest

What does this MR do?

Migrates ee/spec/javascripts/epic/components/sidebar_items/sidebar_date_picker_spec to Jest

Conformity

• [-] Changelog entry
• [-] Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Closes #32462 (closed)