Some `az functionapp` commands don't work for Flex Consumption SKU

### Describe the bug

When using the Flex Consumption SKU, some commands get an error message citing an API version issue. An example of this is when assigning a user-assigned identity to the function app (either during creation or after creation).

This seems like it should work for any command which does a GET-modify-PUT loop from the App Service / Functions commands. It does not impact specific Flex Consumption commands, presumably because they use an alternative path. The issue seems to be for shared commands.

### Related command

`az functionapp identity assign --resource-group --identities --name --debug`

### Errors

> Site.FunctionAppConfig is invalid. It is only supported for 2023-12-01 api-version or newer

### Issue script & Debug output

Truncated to relevant response content:

```
cli.azure.cli.core.sdk.policies: Response content:
cli.azure.cli.core.sdk.policies: {"Code":"BadRequest","Message":"Site.FunctionAppConfig is invalid. It is only supported for 2023-12-01 api-version or newer.","Target":null,"Details":[{"Message":"Site.FunctionAppConfig is invalid. It is only supported for 2023-12-01 api-version or newer."},{"Code":"BadRequest"},{"ErrorEntity":{"ExtendedCode":"51021","MessageTemplate":"{0} is invalid. {1}","Parameters":["Site.FunctionAppConfig","It is only supported for 2023-12-01 api-version or newer."],"Code":"BadRequest","Message":"Site.FunctionAppConfig is invalid. It is only supported for 2023-12-01 api-version or newer."}}],"Innererror":null}
cli.azure.cli.core.azclierror: Traceback (most recent call last):
File "/usr/lib64/az/lib/python3.9/site-packages/knack/cli.py", line 233, in invoke
cmd_result = self.invocation.execute(args)
File "/usr/lib64/az/lib/python3.9/site-packages/azure/cli/core/commands/__init__.py", line 666, in execute
raise ex
File "/usr/lib64/az/lib/python3.9/site-packages/azure/cli/core/commands/__init__.py", line 733, in _run_jobs_serially
results.append(self._run_job(expanded_arg, cmd_copy))
File "/usr/lib64/az/lib/python3.9/site-packages/azure/cli/core/commands/__init__.py", line 703, in _run_job
result = cmd_copy(params)
File "/usr/lib64/az/lib/python3.9/site-packages/azure/cli/core/commands/__init__.py", line 336, in __call__
return self.handler(*args, **kwargs)
File "/usr/lib64/az/lib/python3.9/site-packages/azure/cli/core/commands/command_operation.py", line 121, in handler
return op(**command_args)
File "/usr/lib64/az/lib/python3.9/site-packages/azure/cli/command_modules/appservice/custom.py", line 1288, in assign_identity
webapp = _assign_identity(cmd.cli_ctx, getter, setter, identity_role=role, identity_scope=scope)
File "/usr/lib64/az/lib/python3.9/site-packages/azure/cli/core/commands/arm.py", line 721, in assign_identity
resource = setter(resource)
File "/usr/lib64/az/lib/python3.9/site-packages/azure/cli/command_modules/appservice/custom.py", line 1283, in setter
poller = _generic_site_operation(cmd.cli_ctx, resource_group_name, name, 'begin_create_or_update',
File "/usr/lib64/az/lib/python3.9/site-packages/azure/cli/command_modules/appservice/_appservice_utils.py", line 21, in _generic_site_operation
if extra_parameter is None else operation(resource_group_name,
File "/usr/lib64/az/lib/python3.9/site-packages/azure/core/tracing/decorator.py", line 76, in wrapper_use_tracer
return func(*args, **kwargs)
File "/usr/lib64/az/lib/python3.9/site-packages/azure/mgmt/web/v2023_01_01/operations/_web_apps_operations.py", line 17008, in begin_create_or_update
raw_result = self._create_or_update_initial(
File "/usr/lib64/az/lib/python3.9/site-packages/azure/mgmt/web/v2023_01_01/operations/_web_apps_operations.py", line 16870, in _create_or_update_initial
raise HttpResponseError(response=response, model=error, error_format=ARMErrorFormat)
azure.core.exceptions.HttpResponseError: Operation returned an invalid status 'Bad Request'
Content: {"Code":"BadRequest","Message":"Site.FunctionAppConfig is invalid. It is only supported for 2023-12-01 api-version or newer.","Target":null,"Details":[{"Message":"Site.FunctionAppConfig is invalid. It is only supported for 2023-12-01 api-version or newer."},{"Code":"BadRequest"},{"ErrorEntity":{"ExtendedCode":"51021","MessageTemplate":"{0} is invalid. {1}","Parameters":["Site.FunctionAppConfig","It is only supported for 2023-12-01 api-version or newer."],"Code":"BadRequest","Message":"Site.FunctionAppConfig is invalid. It is only supported for 2023-12-01 api-version or newer."}}],"Innererror":null}

cli.azure.cli.core.azclierror: Operation returned an invalid status 'Bad Request'
az_command_data_logger: Operation returned an invalid status 'Bad Request'
```

### Expected behavior

The command should complete without errors as it does for other SKUs.

### Environment Summary

This was originally found using Cloud Shell (below), but seems to also reproduce on 2.66.

```
az --version
azure-cli 2.65.0 *

core 2.65.0 *
telemetry 1.1.0

Extensions:
ai-examples 0.2.5
containerapp 0.3.53
ml 2.30.1
ssh 2.0.5

Dependencies:
msal 1.31.0
azure-mgmt-resource 23.1.1
```

### Additional context

I believe this to be rooted in the version of azure-mgmt-web being referenced. The current version is 7.2.0 (from 2023-11-19). The latest version is 7.3.1 (from 2024-08-19). With the newer version, the default version will move to 2024-04-01, which should be tolerated.