fix(offers): remove force destroy of application offers

Removes force removal of application offers, but rather errors out if there are
existing integrations with the offer that must be removed first. This is a much
cleaner way to destroy offers as the use of the `force` flag may leave the Juju
state with leftover artefacts.

internal/juju/offers.go

@@ -192,33 +192,18 @@ func (c offersClient) DestroyOffer(input *DestroyOfferInput) error {
 	defer func() { _ = conn.Close() }()
 
 	client := applicationoffers.NewClient(conn)
-	offer, err := client.ApplicationOffer(input.OfferURL)
-	if err != nil {
-		return err
-	}
 
-	forceDestroy := false
-	//This code loops until it detects 0 connections in the offer or 3 minutes elapses
-	if len(offer.Connections) > 0 {
-		end := time.Now().Add(5 * time.Minute)
-		for ok := true; ok; ok = len(offer.Connections) > 0 {
-			//if we have been failing to destroy offer for 5 minutes then force destroy
-			//TODO: investigate cleaner solution (acceptance tests fail even if timeout set to 20m)
-			if time.Now().After(end) {
-				forceDestroy = true
-				break
-			}
-			time.Sleep(10 * time.Second)
-			offer, err = client.ApplicationOffer(input.OfferURL)
-			if err != nil {
-				return err
-			}
+	end := time.Now().Add(10 * time.Minute)
+	for {
+		if time.Now().After(end) {
+			return fmt.Errorf("failed to destroy offer %q, timeout reached", input.OfferURL)
+		}
+		err = client.DestroyOffers(false, input.OfferURL)
+		if err == nil {
+			break
 		}
-	}
 
-	err = client.DestroyOffers(forceDestroy, input.OfferURL)
-	if err != nil {
-		return err
+		time.Sleep(10 * time.Second)
 	}
 
 	return nil