Naming things is hard.
pgjdbc 13.0 will probably interfere with PostgreSQL 13.0 in a near future.
Believe me or not, but we did have exactly the same discussion a year ago:
https://www.postgresql.org/message-id/CADK3HH%2Bivxqe1kzBShk_XZjwVjYWcDznUDNtC9%3DTbexO6ZYZ1A%40mail.gmail.com
The suggestion was "42" as a major version to avoid clash with database
version:
https://www.postgresql.org/message-id/CAB%3DJe-HraoNEWyNFEUSxGjRpH-gC78jHXvDoxnH%2B0wBe%3Dc1rNg%40mail.gmail.com
Should we make it happen? )
Vladimir