Guacamole and Gitea fail because Cannot access AAD_TENANT_ID variable

[anatbal]

AAD_TENANT_ID is no longer an app setting in the api webapp, but rather a secret in KeyVault. The api app setting now reads from keyvault @Microsoft.KeyVault(SecretUri=https://<tre_id>.vault.azure.net/secrets/auth-tenant-id/secretno).

However, when guacamole and gitea are created in Terraform, they referenced this core app setting value as a data element; but it's no longer the value. This resulted in an incorrect value in the guac app setting.

It would be better if we added the AAD_TENANT_ID to the workspace keyvault when we created the workspace and then guacamole and gitea workspace services could reference it, rather than reference core settings.