FWIW, most of the literature on the topic of that particular "risk" implies no evidence of causation. The same correlation applies to alcohol, cigarettes, many prescription drugs, and even simple severe emotional distress. The primary factors for psychosis remain genetic in most cases.
Not only is cannabis not specifically implicated, but no statistically significant correlation has been identified above or beyond much more common and legal substances. Calling out "risk of psychosis" for cannabis would be like calling out "risk of psychosis" for hiking (due to the associated risk of Lyme disease, which itself is implicated in psychosis).
From one long term study:
"Cannabis use has increased dramatically over the past few decades whereas the rate of psychosis has not increased."