Check driver configs validity (formally + kernel headers) in advance

[leodido]

Motivation

Currently, the DBG (driver build grid) starts only when a PR (editing files under driverkit folder) gets merged into the master.

Feature

In order to avoid having to merge to see if a set of prebuilt drivers build, I'd like the build step of DBG to run with --dryrun option on PR branches.

This will, at least, enforce in advance that the DBG config files are formally correct and that driverkit tool can find the kernel headers for every config.

Additional context

Do this as soon https://github.com/falcosecurity/driverkit/issues/52 is done.

[leodido]

This has been done by me following another approach and integrating it into the prebuilt drivers pipeline (friendly called DBG).

Look:

• https://github.com/falcosecurity/test-infra/blob/master/driverkit/utils/checkfiles
• https://github.com/falcosecurity/test-infra/blob/6642926d6e5e052cd0d7179f8f77bb0c3436f541/driverkit/Makefile#L22