Keys in key vault can't be updated via Bicep

**Bicep version**
Bicep CLI version 0.9.1 (a2950a16df)

**Describe the bug**
Once a key with an expiration is created in key vault, the expiration date can not be updated in Bicep when performing a deployment update.
The deployment will error with the following
{"status":"Failed","error":{"code":"DeploymentFailed","message":"At least one resource deployment operation failed. Please list deployment operations for details. Please see https://aka.ms/DeployOperations for usage details.","details":[{"code":"BadRequest","message":"{\r\n \"error\": {\r\n \"code\": \"KeyCreationParametersDidNotMatchExistingKey\",\r\n \"message\": \"[KeyCreationParametersDidNotMatchExistingKey (BadRequest)] The key 'thisIsAsecret2' already exists, but the specified key creation parameters did not match that of the existing key (The existing key has an expiration date of '9/20/2022 9:26:16 AM', which doesn't match the given expiration date '9/20/2022 9:42:56 AM'.). This API can only be used for creating the first version of a new key (no subsequent versions
can be created, and existing keys cannot be updated).\"\r\n }\r\n}"}]}}

**To Reproduce**
Steps to reproduce the behavior:
1. Create the secret in exhisting KV with BICEP. az deployment group create --resource-group "rmurphyaxa-testing" --template-file main.bicep
```bicep
//~~~~~~~~~~~~~~~~~~~~ Key Vault ~~~~~~~~~~~~~~~~~//
resource keyVault 'Microsoft.KeyVault/vaults@2019-09-01' existing = {
name: 'rmurphyaxa-test-kv2'
}
//~~~~~~~~~~~~~~~~~~~~ Key ~~~~~~~~~~~~~~~~~//
resource keys 'Microsoft.KeyVault/vaults/keys@2021-11-01-preview' = {
parent: keyVault
name: 'thisIsAsecret2'
properties: {
attributes: {
enabled: true
exp: 1663666976
}
kty: 'RSA' // RSA

rotationPolicy: {
attributes: {
expiryTime: 'P28D'
}
lifetimeActions: [
{
action: {
type: 'rotate'
}
trigger: {
timeBeforeExpiry: 'P7D'
}
}
]
}
}
}
```
2. Update the properties.attributes.exp date to a later datetime. in exhisting KV with BICEP. Rerun deployment.
e.g.
```
properties: {
attributes: {
enabled: true
exp: 1663686976
}
```
4. Error will be raised stating that the secret already exists and cannot be updated.

Start by reproducing the deployment with the provided main.bicep example and the Microsoft.KeyVault/vaults/keys@2021-11-01-preview resource type. Compare the generated resource definition with Azure Key Vault's behavior when exp changes, then inspect the corresponding type definition. Done means the issue has a verified type-definition fix or a confirmed service limitation documented with the reproduction and error.

Written by the indexing model from the issue text.