Add GlTabs to app/assets/javascripts/ide/components/repo_tabs.vue

What does this MR do?

Adds GlTabs to app/assets/javascripts/ide/components/repo_tabs.vue. I'm new to working with vue, stylistically this change looks similar to how the tabs looked before the change. I'm open to any changes or suggestions that I may have missed.

fixes #230726 (closed)

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Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers