Synapse Activate via Bicep

While I can activate Synapse after double encryption via portal or AZ CLI (w/o --ids). I cannot get bicep code to work.

See code and error message (key name is masked).

```bicep
resource synapseWorkspaceParent 'Microsoft.Synapse/workspaces@2021-06-01' existing = {
name: p_workspaceName
}

resource activateWS 'Microsoft.Synapse/workspaces/keys@2021-06-01' = {
name: p_workspaceName
parent: synapseWorkspaceParent
properties: {
isActiveCMK: p_isActiveCMK
keyVaultUrl: p_keyUrl
}
}
```

```
The resource operation completed with terminal provisioning state 'Failed'.\",\r\n \"details\": [\r\n {\r\n \"code\": \"DeploymentFailed\",\r\n \"message\": \"At least one resource deployment operation failed. Please list deployment operations for details. Please see https://aka.ms/DeployOperations for usage details.\",\r\n \"details\": [\r\n {\r\n
\"code\": \"BadRequest\",\r\n \"message\": \"{\\r\\n \\\"error\\\": {\\r\\n \\\"code\\\": \\\"CannotAddWorkspaceKey\\\",\\r\\n \\\"message\\\": \\\"Workspace Key Vault URL https://kv-dummykeyprodeastus.vault.azure.net/keys/key-cmk-dummykeyprodeastus already exists for workspace key: key-cmk-dummykeyprodeastus\\\"\\r\\n }\\r\\n}\"\r\n }\r\n ]\r\n }\r\n ]\r\n }\r\n}"}]}}
```

Start with the Bicep declarations for Microsoft.Synapse/workspaces and Microsoft.Synapse/workspaces/keys@2021-06-01, then reproduce the deployment using the supplied error. Check whether the resource declaration and existing workspace key behavior match Azure's expected activation flow; done means a documented Bicep deployment path works without the CannotAddWorkspaceKey failure.

Written by the indexing model from the issue text.