PowerShell: "The variable '$elapsed' cannot be retrieved because it has not been set."

When I now log in to Azure Cloud Shell using PowerShell I get this error:

```
InvalidOperation: /opt/microsoft/powershell/7/profile.ps1:268
Line |
268 | if($elapsed -gt '1000')
| ~~~~~~~~
| The variable '$elapsed' cannot be retrieved because it has not been set.
```
here's what is happening:

The profile file `/opt/microsoft/powershell/7/profile.ps1` is part of the Azure Cloud Shell.

I have `Set-StrictMode -Version latest` in my PowerShell profile. If I remove this the error goes away.

I think the default for Azure Cloud Shell PowerShell should use strict mode to catch unnecessary issues.