Keep high priority deps separate from regular deps

Should improve performance slightly by not having to separate them
out again later, and if a module was both a normal and high priority
dep that will now be reflected in the dependency hierarchy in case we
want to find instances of those later. (for example, to remove them
and remove high_priority_deps)

Bug: 376345875
Test: m nothing --no-skip-soong-tests
Change-Id: Ie344aeca2331efb003bb9de4c6a097305ceaeb81