feat: webhook does not return error on 'instance not found'.

This case is probably caused by a webhook event that was meant for
another runner controller / manager. No need to report this as
error, we can simply ignore this and avoid noise in the logs.

apiserver/controllers/controllers.go

@@ -19,6 +19,7 @@ import (
 	"io/ioutil"
 	"log"
 	"net/http"
+	"strings"
 
 	"garm/apiserver/params"
 	"garm/auth"
@@ -103,6 +104,11 @@ func (a *APIController) handleWorkflowJobEvent(w http.ResponseWriter, r *http.Re
 
 	if err := a.r.DispatchWorkflowJob(hookType, signature, body); err != nil {
 		log.Printf("failed to dispatch work: %s", err)
+		// in this case we probably got a webhook that was not meant for us
+		// no need to return an error
+		if strings.Contains(err.Error(), "fetching instance by name: not found") {
+			return
+		}
 		handleError(w, err)
 		return
 	}
@@ -183,7 +189,6 @@ func (a *APIController) FirstRunHandler(w http.ResponseWriter, r *http.Request)
 	}
 	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(newUser)
-
 }
 
 func (a *APIController) ListCredentials(w http.ResponseWriter, r *http.Request) {