chore: remove auth guard from get request to courses

[Wystov]

• [x] I followed naming convention rules

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🤔 This is a ...

• [x] Other

🔗 Related issue link

rs-site-issue#404

💡 Background and solution

As a part of integration of courses dates with rs-site, auth guard from get request to api/v2/courses was removed.

☑️ Self Check before Merge

⚠️ Please check all items below before review. ⚠️

• [x] Database migration is added or not needed
• [x] Documentation is updated/provided or not needed
• [x] Changes are tested locally