ci: increase trivy scan timeout on cloud image

[davidspek]

Summary

Looks like the trivy image scanning on the cloud image is timing out because it is large. This PR doubles the timeout to 10m on that image.

Test Plan

Checklist

• [ ] If required, I have updated the Plural documentation accordingly.
• [ ] I have added tests to cover my changes.
• [ ] I have added a meaningful title and summary to convey the impact of this PR to a user.
• [ ] I have added relevant labels to this PR to help with categorization for release notes.