Ensure scale set exists

Github will remove inactive scale sets after 7 days. This change
ensures the scale set exists in github before spinning up the listener.

Signed-off-by: Gabriel Adrian Samfira <gsamfira@cloudbasesolutions.com>

params/requests.go

@@ -636,6 +636,7 @@ type UpdateScaleSetParams struct {
 	GitHubRunnerGroup *string        `json:"runner_group,omitempty"`
 	State             *ScaleSetState `json:"state"`
 	ExtendedState     *string        `json:"extended_state"`
+	ScaleSetID        int            `json:"-"`
 }
 
 // swagger:model CreateGiteaEndpointParams