Added sketch compile workflow

[cmaglie]

Added sketch compile workflow to build examples for a bunch of boards.
Copied and adapted from https://github.com/arduino-libraries/Arduino_NetworkConfigurator/blob/main/.github/workflows/compile-examples.yml

[per1234]

You removed the platform dependency information in 3268332 (#7).

That jobs.<job_id>.strategy.matrix.include system is useful to avoid code duplication in the workflow when the same relatively complex configuration is present for multiple compilation targets (I provide a detailed explanation here), but is fairly unintuitive and significantly increases the complexity of the workflow. So it is definitely reasonable to eschew it in this case. However, if you are going to do that then you must define the platform dependency of the target in strategy.matrix.board[*].platform. You can see an example of that approach in the canonical "template" workflow:

https://github.com/per1234/.github/blob/e6a938a7e56096943e02fcb7a7770f1d5c8d6fed/workflow-templates/compile-examples.yml#L44-L45

https://github.com/per1234/.github/blob/e6a938a7e56096943e02fcb7a7770f1d5c8d6fed/workflow-templates/compile-examples.yml#L56

[cmaglie]

Even if the tests are failing, the workflow is ready to go. I'm going to merge it so that the remaining warnings/errors can be fixed in a separate PR.

[eigen-value]

LGTM

[cmaglie]

That jobs.<job_id>.strategy.matrix.include system is useful to avoid code duplication in the workflow when the same relatively complex configuration is present for multiple compilation targets (I provide a detailed explanation here), but is fairly unintuitive and significantly increases the complexity of the workflow. So it is definitely reasonable to eschew it in this case. However, if you are going to do that then you must define the platform dependency of the target in strategy.matrix.board[*].platform. You can see an example of that approach in the canonical "template" workflow:

Thanks for the explanation @per1234. In this case, the dependency tree is very simple and straightforward, but good to know for future projects!