releng-azure: Use port name to install Azure CLI

To overcome package name changing on default Python version updates.

Approved by: gjb (re), delphij (re)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D41453

(cherry picked from commit 0fe6998d8ad0bf54c237c8f513bf00cab547b561)
(cherry picked from commit 80496f42b6a9c13664f6228602fd21bf7a4500a5)