[BUG]Not able to remove gateways after removing it from the code.

### Release version

v6.0.1.1

### Describe the bug

In the api code, if we add the gateway, we are able to see the gateway in apim.
If we delete the gateway in api code, the gateway is not getting deleted.

### Expected behavior

Under artifacts -> gateways -> gateway name -> apis -> yourapi --> Gateway is added in apim api collection..
Under artifacts -> gateways -> gateway name -> apis -> yourapi [remove this one] --> Gateway should be removed from apim api collection

### Actual behavior

Under artifacts -> gateways -> gateway name -> apis -> yourapi --> Gateway is added in apim api collection.. [working as expected]
Under artifacts -> gateways -> gateway name -> apis -> yourapi [remove this one] --> Gateway is not getting removed from apim api collection

### Reproduction Steps

Under artifacts -> gateways -> gateway name -> apis -> yourapi --> Gateway is added in apim api collection.. [working as expected]
Under artifacts -> gateways -> gateway name -> apis -> yourapi [remove this one] --> Gateway is not getting removed from apim api collection

Iniziare riproducendo il problema in release v6.0.1.1 utilizzando il percorso descritto artifacts → gateways → gateway name → apis, verificando innanzitutto che l’aggiunta del gateway aggiorni la raccolta di API di APIM. Tracciare la gestione della rimozione e verificare che l’eliminazione del riferimento all’API faccia scomparire il gateway dalla raccolta di API di APIM.

Scritto dal modello di indicizzazione a partire dal testo della issue.