Working solution for newer versions of Jenkins

[ovezthaking]

What was changed

1. Updated the Jenkins base image to a newer LTS version.
2. Updated dependency installation in Jenkins pipeline to handle system package restrictions.
3. Added a dedicated Docker agent image for Python jobs.
4. Fixed code formatting/indentation in the sample app.

Outcome

1. Pipeline is more robust when installing Python dependencies.
2. Jenkins and agent setup is aligned with newer versions.
3. Repository now includes a ready-to-use Python Docker agent image.