Is it valid for the PX4 project to use `px4_sitl` as the default target for running cppcheck, clang-tidy, etc

[jrn90]

px4_sitl is the default target for running a lot of the security scanning tools (cppcheck, clang-tidy, lcov, tests). We need to determine if this is a valid approach for the PX4 project.

Acceptance Criteria

• [ ] Determine why the px4_sitl target is used for cppcheck, clang-tidy, code coverage, and tests.

[jrn90]

px4_sitl as a target for code scanning could be considered valid since it is pulling in what I would consider the "px4 framework" code. That is, code that is essential to running any px4 enabled firmware. Without that code you aren't flying with PX4.

This does exclude code that would be specific to different boards. This code would be drivers, mixers, board specific code.

Initial approach would be an additional make target. However, since px4_sitl targets POSIX and a firmware board would target NuttX, this might be a great effort depending on tooling.

[jrn90]

Answered above.