security/py-bcrypt: Upgrade port to 4.3.0

* Add upstream version constraints where possible
* port{clippy|fmt|lint} housekeeping
* Remove devel/py-cffi from ${BUILD_DEPENDS}, and ${RUN_DEPENDS}, it is
  no longer required
* Use ${DISTVERION} over ${PORTVERSION}, following the practices set out in,
  the FreeBSD Porter's Handbook

Co-authored-by: Siva Mahadevan <me@svmhdvn.name>
PR:		276049
Approved by:	jrm (mentor)
Differential Revision:	https://reviews.freebsd.org/D50803
Changelog:	https://github.com/pyca/bcrypt/tree/main?tab=readme-ov-file#430