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