No, it is not possible to transfer your data, such as trophies and DLC, from the PS5 version to the Steam version.
*This article is for the Steam version.
As for the PS5 version, since the publisher Sony Interactive Entertainment (SIE) is in charge of sales and customer support, KOEI TECMO GAMES is unable to respond to inquiries.
For PS5 version of "Rise of the Ronin", please refer to Help of PlayStation Support, and if it does not resolve the issue, please consider contacting PlayStation Support for assistance.