Official Azure CLI Formula was removed
Last versions were
azure-cli@1 requires the following formula to be installed:
node 9.9.0 Platform built on V8 to build network applications

Recent formula history

FX Coudert azure-cli@1: remove
ilovezfs azure-cli@1: depend on python instead of :python
ilovezfs azure-cli@1
ilovezfs azure-cli@1
Derek Bekoe azure-cli@1 (new formula)

Formula code at GitHub