Get-AzVm does not return all UserAssignedIdentities

### Description

We have over 100 user-assigned managed identities on each of our virtual machines. We can see them in the portal.

However, when running the following PowerShell commands in the Azure Cloud Shell,

$vm = Get-AzVM -ResourceGroupName $rg -Name $vmName
$assigned = $vm.Identity.UserAssignedIdentities.Keys
$assigned.Count

We only get 70 identities.

### Issue script & Debug output

```PowerShell
$vm = Get-AzVM -ResourceGroupName $rg -Name $vmName
$assigned = $vm.Identity.UserAssignedIdentities.Keys
$assigned.Count

70
```

### Environment data

```PowerShell
Name Value
---- -----
PSVersion 7.3.3
PSEdition Core
GitCommitId 7.3.3
OS Linux 5.4.0-1105-azure #111~18.04.1-Ubuntu SMP Fri Mar 3 22:47:43 UTC 2023
Platform Unix
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1
WSManStackVersion 3.0
```

### Module versions

```PowerShell
ModuleType Version PreRelease Name ExportedCommands
---------- ------- ---------- ---- ----------------
Script 2.12.1 Az.Accounts {Add-AzEnvironment, Clear-AzConfig, Clear-AzContext, Clear-AzDefault…}
Script 5.7.0 Az.Compute {Add-AzImageDataDisk, Add-AzVhd, Add-AzVMAdditionalUnattendContent, Add-AzVMDataDisk…}
Script 5.6.0 Az.Network {Add-AzApplicationGatewayAuthenticationCertificate, Add-AzApplicationGatewayBackendAddressPool, Add-AzApplica…
Script 6.6.0 Az.Resources {Export-AzResourceGroup, Export-AzTemplateSpec, Get-AzDenyAssignment, Get-AzDeployment…}
Script 5.5.0 Az.Storage {Add-AzRmStorageContainerLegalHold, Add-AzStorageAccountManagementPolicyAction, Add-AzStorageAccountNetworkRu…
Script 1.1.0 Az.Tools.Predictor {Disable-AzPredictor, Enable-AzPredictor, Open-AzPredictorSurvey, Send-AzPredictorRating}
Script 0.0.0.10 AzureAD.Standard.Preview {Add-AzureADApplicationOwner, Add-AzureADDeviceRegisteredOwner, Add-AzureADDeviceRegisteredUser, Add-AzureADD…
Script 0.9.3 AzurePSDrive
```

### Error output

```PowerShell
WARNING: Upcoming breaking changes in the cmdlet 'Resolve-AzError' :
The `Resolve-Error` alias will be removed in a future release. Please change any scripts that use this alias to use `Resolve-AzError` instead.
Note : Go to https://aka.ms/azps-changewarnings for steps to suppress this breaking change warning, and other information on breaking changes in Azure PowerShell.
```