The TestIdfRootDependency tests (test_basic_build,
test_build_only_when_required, test_cleanup_unused) were introduced in
MR 39704 to validate the idf_extra_components.yml root dependency
feature. This feature relies on component manager integration that is
not yet implemented in the cmakev2 build system, causing all three
tests to fail when run with --buildv2.
Skip these tests for cmakev2 using the buildv2_skip marker until root
components support is added (IDF-14259).
Signed-off-by: Frantisek Hrbata <frantisek.hrbata@espressif.com>