Tested with NGINX Instance Manager 2.21, updated base image

[fabriziofiorucci]

Proposed changes

Base image updated from Ubuntu 22.04 to 24.04, tested with NGINX Instance Manager 2.21

Checklist

Before creating a PR, run through this checklist and mark each as complete:

• I have read the contributing guidelines.
• I have signed the F5 Contributor License Agreement (CLA).
• If applicable, I have added tests that prove my fix is effective or that my feature works.
• If applicable, I have checked that any relevant tests pass after adding my changes.
• If this is a new demo, I have added the demo info to both the CODEOWNERS and README.md.
• I have updated any relevant documentation (README.md and/or CHANGELOG.md).