linux error: az CLI command not found

Debian 11 (Bullseye) running in WSL2 (Win 11). core tools were installed with NPM and the az CLI via the MS azure-cli DEB package.

any command that involves talking to azure just fails with:
```
func azure functionapp list-functions helloworld
Unable to connect to Azure. Make sure you have the `az` CLI or `Az.Accounts` PowerShell module installed and logged in and try again`
```

`which az` shows: `/usr/bin/az`
`whereis az` shows: `az: /usr/bin/az /opt/az/bin/az.bat /opt/az/bin/az`

`func --version` : `4.0.3971`
`az --version` : `azure-cli 2.33.1`

Reproduce `func azure functionapp list-functions helloworld` in Debian 11 under WSL2 using the reported `func` and `az` versions. Start by tracing how the command detects and invokes `/usr/bin/az`; done means Azure commands connect successfully when the Azure CLI is installed and logged in.

Written by the indexing model from the issue text.