math/z3: Update 4.14.1.0 => 4.15.3.0

[alven]

Summary

Changelogs:

• https://github.com/Z3Prover/z3/blob/master/RELEASE_NOTES.md#version-4153
• https://github.com/Z3Prover/z3/compare/z3-4.14.1...z3-4.15.3

• Pet portfmt(1) and portlint(1)

Test Plan

For every {amd64, i386} × {14.3, 13.5}:

• Successful poudriere testport
• Successful run-testing

[arrowd]

Thanks!

[yuri]

Approved.

Please don't forget to bump all dependencies.

Thanks,
Yuri