fix(module/asg): Execute pip to install Python packages (corner case in CI/CD pipeline)

[sebastianczech]

Description

PR delivers fix for one corner case while executing Terraform code in CI/CD pipelines.

Motivation and Context

If Terraform code is executed in CI/CD pipeline, then:

• after first terraform apply whole infrastructure is being deployed and while installing Lambda, locally on agent executing pipeline there are downloaded Python packages and installed-pan-os-python is set from known after apply to false
• next time when CI/CD pipeline is executed on different agent, terraform apply will not install Python packages, because there is no change for installed-pan-os-python, it's still false as local Python packages are not existing on new agent
• Lambda is being deploying without required Python packages

PR changes that behaviour - instead of using false, when there are no Python packages, we are using timestamp(), which forces to execute pip install every time, when there are no Python packages.

How Has This Been Tested?

Code was tested locally by:

• deploying examples/centralized_design_autoscale
• manually removing all Python packages from modules/asg/scripts, stored on local disk
• executing terraform apply one more time for examples/centralized_design_autoscale
• checking in AWS console if Lambda contains all Python packages after every terraform apply

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist

• [x] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes if appropriate.
• [x] All new and existing tests passed.

[sebastianczech]

/idempotence paths="examples/isolated_design_autoscale"

Testing job ID: 7015635672 Job result: SUCCESS