Resolve "Nginx should accept ECDSA certificates"

What does this MR do?

This MR adds new ciphers in the different Nginx configuration file, so both RSA and ECDSA certificates are accepted by default by the web server.

Are there points in the code the reviewer needs to double check?

No, Nginx (OpenSSL) picks the right ciphers that correspond to its certificate.

Why was this MR needed?

#49888 (moved)

EC not only for ssh keys, but also for the web.

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Conforms to the code review guidelines
  • Has been reviewed by a UX Designer
  • Has been reviewed by a Frontend maintainer
  • Has been reviewed by a Backend maintainer
  • Has been reviewed by a Database specialist
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• If you have multiple commits, please combine them into a few logically organized commits by squashing them
• Internationalization required/considered
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

omnibus-gitlab#3713 (closed)

Closes #49888 (moved)