cad/verilator: Update 5.038 => 5.0.40

[alven]

Summary

Changelogs:

• https://github.com/verilator/verilator/blob/master/Changes#verilator-5040-2025-08-30

• Remove workarounds for fixed issue https://github.com/verilator/verilator/issues/3132
• Don't strip DBG_EXECUTABLES as they are Perl scripts
• Pet portclippy(1) and portfmt(1)

Test Plan

For every {amd64} × {14.3, 13.5}:

• Successful poudriere testport
• Successful run-testing

[yuri]

Approved.

Thanks,
Yuri