#1376 Unify robots file

[radoslavzeman]

Description

Implement robots file according to OLO/Marianum.

Testing

Visit /robots.txt, you should be redirected to /api/robots and see robots file according to NEXT_PUBLIC_DEPLOYMENT variable.
For all non-prod:

      User-Agent: *
      Disallow: /

For prod:

        User-agent: *
        Disallow: /api/

Notes

I changed also env vars to have the same approach in projects from NEXT_PUBLIC_IS_STAGING to NEXT_PUBLIC_DEPLOYMENT.
Other changes in envs are just reorder to have the same order in all files to be able to check them easily.

[github-actions]

Test build pipeline info 🚀

Changes in the code and tag info:

➡️ Changes in strapi: false

➡️ Changes in next: true

We are going to build 🚢

🔜 next

🥳 Bratiska-cli successfully built an image from path: next/

[Ty-ci]

🙌 nice!