Traceback when not logged in to azure and attempting to deploy shm

:white_check_mark: Checklist

[x] I have searched open and closed issues for duplicates.
[x] This is a problem observed when deploying a Data Safe Haven.
[x] I can reproduce this with the latest version.
[x] I have read through the documentation.
[x] This isn't an open-ended question (open a discussion if it is).

:computer: System information

Operating System: macOs
Data Safe Haven version: develop

:package: Packages

List of packages

```none Paste list of packages here ```

:no_entry_sign: Describe the problem

:deciduous_tree: Log messages

Relevant log messages

```none (data-safe-haven) deploydsh@403b243ad50e:/workspaces/data-safe-haven$ dsh shm deploy Please authenticate with Azure: run 'az login' using infrastructure administrator credentials. Error getting account information from Azure CLI. ╭─────────────────────────────── Traceback (most recent call last) DataSafeHavenAzureError: Error getting account information from Azure CLI. ```

:recycle: To reproduce

Run dsh shm deploy without first using az login

alan-turing-institute / data-safe-haven