📝 Configure environments for Jenkins AMI

[sydrawat01]

• Create user specific environments to run GitHub actions with user defined pkrvars.
• Update the packer-validate.yml (CI) action runner to use GHA environments.
• Add build action runner (CD) for custom AMI.

[sydrawat01]

Docs for github actions environments.

• We will create environments in the organization master repo, which will then be configured to use environment variables defined at organization level to run the Ci/CD pipelines dynamically.