Change button variant to confirm in the releases page and form

What does this MR do and why?

Fix the button variant success -> confirm

Screenshots or screen recordings

As-is	To-be

How to set up and validate locally

1. Go to one project on the GDK
2. Go to Deployments > Releases - I used http://127.0.0.1:3000/gnuwget/Wget2/-/releases
3. Check the button on the right top of the main page New release
4. Click the New release and fill the required form fields
5. Check the button on the bottom Create release

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.