CMake failbuild tests like test_add_resource_options sometimes don't find Qt6CoreTools.cmake

Test: qtbase/tests/auto/cmake/test_add_resource_options/CMakeLists.txt

On Andreas's Linux machine, the transitive call of find_package(Qt6CoreTools) done by find_package(Qt6Core) fails to find Tools.

That's because the HINTS arg we pass is not transitive.

find_package(Qt6Core REQUIRED HINTS ${Qt6Tests_PREFIX_PATH})

Adding an explicit

find_package(Qt6CoreTools REQUIRED HINTS ${Qt6Tests_PREFIX_PATH})

makes it work of course.

It's unclear to me yet why it works locally for me and in the CI.