Output toolchain list during distribution bundle build

[stephanosio]

trafficstars

Problem

Currently, the toolchain list is hard-coded in the distribution bundle setup script. The distribution bundle script assumes that, if not all toolchain directories are locally available, the current distribution bundle is "minimal" and attempts to download the missing toolchain:

https://github.com/zephyrproject-rtos/sdk-ng/blob/15a7071419346beae16222108c97d923a450938e/scripts/template_setup_posix#L118-L139

This causes a problem when the CI does a partial distribution bundle build that does not contain all the normally included toolchains. For example, https://github.com/zephyrproject-rtos/sdk-ng/runs/7240886429?check_suite_focus=true

Solution

While building a distribution bundle in the CI, the toolchain list should be dynamically generated and placed into the distribution bundle setup script.

In addition, the type of the distribution bundle, compatible host operating system, compatible host architecture, and other miscellaneous information should also be added to the distribution bundle script.

Implementation Plan

Introduce a preprocessor and use it to preprocess the distribution bundle scripts.

[stephanosio]

Do this after beta release.

[stephanosio]

Postponing this to 0.16.0 since this is more of a CI issue.