fix: display the relevant number in the error message (#1835)

## Description:
Tiny bug when running `kurtosis clean -a`: if your APIC has more than
one service running in it it will print an error, but print the number
of services it found incorrectly:

```
 --- at ~/kurtosis/kurtosis/container-engine-lib/lib/backend_impls/kubernetes/kubernetes_kurtosis_backend/kubernetes_kurtosis_backend_api_container_functions.go:678 (KubernetesKurtosisBackend.getMatchingApiContainerObjectsAndKubernetesResources) ---
Caused by: Expected at most one API container service in namespace 'kt-crumbling-sky' for enclave with ID '39d662eb74784368a78b35ce9a4f09bf' but found '1'
```

Why did I have more than 1 in this case? I'd added one directly via
`kubectl expose` so the only bug here is the error display.


## Is this change user facing?
YES: only in the weeds of error message logging
<!-- If yes, please add the "user facing" label to the PR -->
<!-- If yes, don't forget to include docs changes where relevant -->

## References (if applicable):
<!-- Add relevant Github Issues, Discord threads, or other helpful
information. -->

Co-authored-by: Omar <Omar>

container-engine-lib/lib/backend_impls/kubernetes/kubernetes_kurtosis_backend/kubernetes_kurtosis_backend_api_container_functions.go

@@ -770,7 +770,7 @@ func (backend *KubernetesKurtosisBackend) getMatchingApiContainerKubernetesResou
  "but found '%v'",
  namespaceName,
  enclaveIdStr,
- len(services),
+ len(servicesForEnclaveId),
  )
  }
  service := servicesForEnclaveId[0]