Remove redundan PATs on refresh mode

[vinokurig]

What does this PR do?

Iterate over personal access token secrets on refresh function. Remove outdated token secrets except the latest refreshed token secret.

Screenshot/screencast of this PR

What issues does this PR fix or reference?

fixes https://github.com/eclipse-che/che/issues/23027

How to test this PR?

• Deploy che with the pr image: quay.io/eclipse/che-server:pr-
• Configure gitlab oauth
• Apply refresh mode
• Start a workspace from gitlab repository with a devfile.
• Go to Dashboard user preferences -> personal access tokens
• See: only one personal access token item is present in the list

PR Checklist

As the author of this Pull Request I made sure that:

• [x] The Eclipse Contributor Agreement is valid
• [x] Code produced is complete
• [x] Code builds without errors
• [x] Tests are covering the bugfix
• [ ] The repository devfile is up to date and works
• [ ] Sections What issues does this PR fix or reference and How to test this PR completed
• [ ] Relevant user documentation updated
• [ ] Relevant contributing documentation updated
• [ ] CI/CD changes implemented, documented and communicated

Reviewers

Reviewers, please comment how you tested the PR when approving it.