Unify Worker Environment Variables systemd/k8s

[agrare]

Handling of worker environment variables was spread across a number of different locations and in a number of cases had to be duplicated for systemd/kubernetes.

This adds a common MiqWorker#environment_variables method that applies to all runtime platforms, as well as specific systemd/container_environment_variables which are merged in depending on the runtime environment.

TODO:

Live test of standard workers, provider workers, opentofu-runner on:

• [x] appliances
• [x] podified
• [x] dev-process

Dependent:

• https://github.com/ManageIQ/manageiq-providers-embedded_terraform/pull/74

[Fryguy]

This is great!

[miq-bot]

Checked commit https://github.com/agrare/manageiq/commit/80d99c9aed9204e2c1db9c3810a8dc73993c3c80 with ruby 3.1.5, rubocop 1.56.3, haml-lint 0.51.0, and yamllint 7 files checked, 0 offenses detected Everything looks fine. :cookie:

[agrare]

Okay I've tested this on openshift/appliances/local-development-environment and all runs correctly, taking out of WIP