Invalid .NET version

### Describe the bug

.NET framework version value in "az functionapp config set" generates warning/error

### Related command

az functionapp config set

### Errors

Invalid version: for runtime dotnet-isolated and os windows. Supported versions for runtime dotnet-isolated and os windows are: ['.4.8', '8', '7', '6']. Run 'az functionapp list-runtimes' for more details on supported runtimes.

### Issue script & Debug output

az functionapp config set name "appname" --resource-group "groupname" --slot "slot" --net-framework-version v7.0

### Expected behavior

It should not produce any error because I've tried using "7.0", "7", "v7" and "v7.0" and they all produce the same message. The warning is displayed even when the command used the correct net-framework-version value.

### Environment Summary

azure-cli 2.57.0

core 2.57.0
telemetry 1.1.0

Extensions:
ai-examples 0.2.5
ml 2.22.0
ssh 2.0.2

Dependencies:
msal 1.26.0
azure-mgmt-resource 23.1.0b2

### Additional context

This warning occurs when we run our ADO pipeline, thus causing the pipeline to fail. This was a new issue since nothing is changed on our pipeline since the last successful run. I think the issue is within the _FunctionAppStackRuntimeHelper which is recently added through this - https://github.com/Azure/azure-cli/blame/87dec2c86a39da9cc056697a92a234da86c97646/src/azure-cli/azure/cli/command_modules/appservice/custom.py#L409