extend support for tasks that use oneOffExecutors (only MatrixProject was supported)

On runCount calc the OneOffExecuters were only counted if task was an
instance of MatrixProject. This approach cause an error when using other
tasks running on oneOffExecuters such as the ones used by
build-flow-plugin.
Replacing MatrixProject by its parent FlyweigthTask solves this issue.
Replacing MatrixProject by its parent FlyweigthTask solves this issue