Migrate deprecated colors variants on GlButton component

Problem

In gitlab-ui@v104 the info variant was removed (see gitlab-ui@2da00cd5), which was marked as a breaking change.

Proposal

To receive further updates for the gitlab-ui package we need to find and resolve all places where we use any deprecated variant.

What should be done?

• variant="info" should be variant="confirm".
• variant="success" should be variant="confirm".