Error when registering Azure Stack Hub

### Describe the bug

When I run the following command in PowerShell:
```
az cloud register --name $environmentName -cloud-config `@$azureCliConfigJson
```

I get the following error:
```
az : ERROR: The command failed with an unexpected error. Here is the traceback:
At line:1 char:1
+ az cloud register --name $environmentName --cloud-config `@$a ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (ERROR: The comm... the traceback::String) [], RemoteException
+ FullyQualifiedErrorId : NativeCommandError

ERROR: list indices must be integers or slices, not str
Traceback (most recent call last):
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\knack/cli.py", line 233, in invoke
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 666, in execute
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 734, in _run_jobs_serially
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 703, in _run_job
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 336, in __call__
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/command_operation.py", line 120, in handler
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 126, in register_cloud
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 71, in _build_cloud
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 50, in _populate_from_metadata_endpoint
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/cloud.py", line 258, in _arm_to_cli_mapper
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/cloud.py", line 249, in _get_processed_arm_endpoint
TypeError: list indices must be integers or slices, not str
To check existing issues, please visit: https://github.com/Azure/azure-cli/issues
```

This is the JSON config file:
```
{
"profile": "2020-09-01-hybrid",
"endpoints": {
"resourceManager": "",
"vmImageAliasDoc": "https://raw.githubusercontent.com/Azure/azure-rest-api-specs/master/arm-compute/quickstart-templates/aliases.json"
},
"suffixes": {
"storageEndpoint": "",
"keyvaultDns": ""
}
}

```

It might be related to the removed support for Azure Stack Hub profiles:
https://github.com/Azure/azure-cli/commit/56c812494ef4706f7c4a639d2fb9d03faf8a7552
https://github.com/Azure/azure-cli/commit/a66bcbdf026e5130abbac76491309aaac9049273
@kairu-ms FYI.

### Related command

```
az cloud register --name $environmentName -cloud-config `@$azureCliConfigJson
```

### Errors

```
az : ERROR: The command failed with an unexpected error. Here is the traceback:
At line:1 char:1
+ az cloud register --name $environmentName --cloud-config `@$a ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (ERROR: The comm... the traceback::String) [], RemoteException
+ FullyQualifiedErrorId : NativeCommandError

ERROR: list indices must be integers or slices, not str
Traceback (most recent call last):
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\knack/cli.py", line 233, in invoke
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 666, in execute
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 734, in _run_jobs_serially
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 703, in _run_job
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 336, in __call__
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/command_operation.py", line 120, in handler
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 126, in register_cloud
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 71, in _build_cloud
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 50, in _populate_from_metadata_endpoint
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/cloud.py", line 258, in _arm_to_cli_mapper
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/cloud.py", line 249, in _get_processed_arm_endpoint
TypeError: list indices must be integers or slices, not str
To check existing issues, please visit: https://github.com/Azure/azure-cli/issues
```

### Issue script & Debug output

```
az : DEBUG: cli.knack.log: File logging enabled - writing logs to 'C:\CloudDeployment\BVTs\Output\AZSDKTOOLSCTQ\CLITestLogs'.
At line:1 char:1
+ az cloud register --name $environmentName --cloud-config `@$a ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (DEBUG: cli.knac...Q\CLITestLogs'.:String) [], RemoteException
+ FullyQualifiedErrorId : NativeCommandError

DEBUG: cli.knack.cli: Command arguments: ['cloud', 'register', '--name', 'AzureStackWlkCloud-Tenant', '--cloud-config', '@C:\\test\\Workloads\\DeveloperExperience\\CLI\\config.json', '--debug']
DEBUG: cli.knack.cli: __init__ debug log:
Cannot enable color.
DEBUG: cli.knack.cli: Event: Cli.PreExecute []
DEBUG: cli.knack.cli: Event: CommandParser.OnGlobalArgumentsCreate [, , ]
DEBUG: cli.azure.cli.core.util: attempting to read file C:\test\Workloads\DeveloperExperience\CLI\config.json as utf-8-sig
DEBUG: cli.azure.cli.core.util: attempting to read file C:\test\Workloads\DeveloperExperience\CLI\config.json as utf-8
DEBUG: cli.azure.cli.core.util: attempting to read file C:\test\Workloads\DeveloperExperience\CLI\config.json as utf-16
DEBUG: cli.knack.cli: Event: CommandInvoker.OnPreCommandTableCreate []
DEBUG: cli.azure.cli.core: Modules found from index for 'cloud': ['azure.cli.command_modules.cloud']
DEBUG: cli.azure.cli.core: Loading command modules:
DEBUG: cli.azure.cli.core: Name Load Time Groups Commands
DEBUG: cli.azure.cli.core: cloud 0.005 1 7
DEBUG: cli.azure.cli.core: Total (1) 0.005 1 7
DEBUG: cli.azure.cli.core: Loaded 1 groups, 7 commands.
DEBUG: cli.azure.cli.core: Found a match in the command table.
DEBUG: cli.azure.cli.core: Raw command : cloud register
DEBUG: cli.azure.cli.core: Command table: cloud register
DEBUG: cli.knack.cli: Event: CommandInvoker.OnPreCommandTableTruncate []
DEBUG: cli.azure.cli.core.azlogging: metadata file logging enabled - writing logs to 'C:\Users\Administrator\.azure\commands\2025-05-24.00-06-12.cloud_register.3928.log'.
INFO: az_command_data_logger: command args: cloud register --name {} --cloud-config {} --debug
DEBUG: cli.knack.cli: Event: CommandInvoker.OnPreArgumentLoad [.add_subscription_parameter at 0x03D67D98>]
DEBUG: cli.knack.cli: Event: CommandInvoker.OnPostArgumentLoad []
DEBUG: cli.knack.cli: Event: CommandInvoker.OnPostCommandTableCreate [.add_ids_arguments at 0x03D67DE8>, .add_cache_arguments at 0x03D96A28>, .update_breaking_change_info at 0x03D96A78>]
DEBUG: cli.knack.cli: Event: CommandInvoker.OnCommandTableLoaded []
DEBUG: cli.knack.cli: Event: CommandInvoker.OnPreParseArgs []
DEBUG: cli.knack.cli: Event: CommandInvoker.OnPostParseArgs [, , .parse_ids_arguments at 0x03D969D8>]
DEBUG: urllib3.connectionpool: Starting new HTTPS connection (1): management.redmond.ext-s31r1304.masd.stbtest.microsoft.com:443
DEBUG: urllib3.connectionpool: https://management.redmond.ext-s31r1304.masd.stbtest.microsoft.com:443 "GET /metadata/endpoints?api-version=2022-09-01 HTTP/1.1" 200 726
DEBUG: cli.azure.cli.core.azclierror: Traceback (most recent call last):
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\knack/cli.py", line 233, in invoke
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 666, in execute
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 734, in _run_jobs_serially
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 703, in _run_job
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 336, in __call__
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/command_operation.py", line 120, in handler
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 126, in register_cloud
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 71, in _build_cloud
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 50, in _populate_from_metadata_endpoint
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/cloud.py", line 258, in _arm_to_cli_mapper
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/cloud.py", line 249, in _get_processed_arm_endpoint
TypeError: list indices must be integers or slices, not str

ERROR: cli.azure.cli.core.azclierror: The command failed with an unexpected error. Here is the traceback:
ERROR: az_command_data_logger: The command failed with an unexpected error. Here is the traceback:
ERROR: cli.azure.cli.core.azclierror: list indices must be integers or slices, not str
Traceback (most recent call last):
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\knack/cli.py", line 233, in invoke
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 666, in execute
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 734, in _run_jobs_serially
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 703, in _run_job
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 336, in __call__
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/command_operation.py", line 120, in handler
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 126, in register_cloud
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 71, in _build_cloud
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 50, in _populate_from_metadata_endpoint
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/cloud.py", line 258, in _arm_to_cli_mapper
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/cloud.py", line 249, in _get_processed_arm_endpoint
TypeError: list indices must be integers or slices, not str
ERROR: az_command_data_logger: list indices must be integers or slices, not str
Traceback (most recent call last):
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\knack/cli.py", line 233, in invoke
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 666, in execute
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 734, in _run_jobs_serially
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 703, in _run_job
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 336, in __call__
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/command_operation.py", line 120, in handler
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 126, in register_cloud
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 71, in _build_cloud
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/cloud/custom.py", line 50, in _populate_from_metadata_endpoint
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/cloud.py", line 258, in _arm_to_cli_mapper
File "D:\a\_work\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/cloud.py", line 249, in _get_processed_arm_endpoint
TypeError: list indices must be integers or slices, not str
To check existing issues, please visit: https://github.com/Azure/azure-cli/issues
DEBUG: cli.knack.cli: Event: Cli.PostExecute []
INFO: az_command_data_logger: exit code: 1
INFO: cli.__main__: Command ran in 1.295 seconds (init: 0.506, invoke: 0.788)
INFO: telemetry.main: Begin splitting cli events and extra events, total events: 1
INFO: telemetry.client: Accumulated 0 events. Flush the clients.
INFO: telemetry.main: Finish splitting cli events and extra events, cli events: 1
INFO: telemetry.save: Save telemetry record of length 7616 in cache file under C:\Users\Administrator\.azure\telemetry\20250524000613763
INFO: telemetry.main: Begin creating telemetry upload process.
INFO: telemetry.process: Creating upload process: "C:\Program Files (x86)\Microsoft SDKs\Azure\CLI2\python.exe C:\Program Files (x86)\Microsoft
SDKs\Azure\CLI2\Lib\site-packages\azure\cli\telemetry\__init__.pyc C:\Users\Administrator\.azure C:\Users\Administrator\.azure\telemetry\20250524000613763"
INFO: telemetry.process: Return from creating process 11812
INFO: telemetry.main: Finish creating telemetry upload process.
```

### Expected behavior

There should be either a user-friendly error message if something is no longer supported, or it should not throw an error.

### Environment Summary

```
azure-cli 2.73.0

core 2.73.0
telemetry 1.1.0

Dependencies:
msal 1.32.3
azure-mgmt-resource 23.3.0

Python location 'C:\Program Files (x86)\Microsoft SDKs\Azure\CLI2\python.exe'
Config directory 'C:\Users\Administrator.S31R1304-DVM\.azure'
Extensions directory 'C:\Users\Administrator.S31R1304-DVM\.azure\cliextensions'

Python (Windows) 3.12.10 (tags/v3.12.10:0cc8128, Apr 8 2025, 11:58:42) [MSC v.1943 32 bit (Intel)]

Legal docs and information: aka.ms/AzureCliLegal

Your CLI is up-to-date.
```

### Additional context

_No response_