hcp: set the status to CANCELLED when a build is

Related to the previous behaviour problem, this changes how the status
of a build is set on HCP Packer, as a cancelled build is different from
a failed one, we can set it to the appropriate state on cancellation.

internal/hcp/registry/types.bucket.go

@@ -569,7 +569,11 @@ func (b *Bucket) completeBuild(
 	}
 
 	if buildErr != nil {
-		err := b.UpdateBuildStatus(ctx, buildName, models.HashicorpCloudPackerBuildStatusFAILED)
+		status := models.HashicorpCloudPackerBuildStatusFAILED
+		if ctx.Err() != nil {
+			status = models.HashicorpCloudPackerBuildStatusCANCELLED
+		}
+		err := b.UpdateBuildStatus(context.Background(), buildName, status)
 		if err != nil {
 			log.Printf("[ERROR] failed to update build %q status to FAILED: %s", buildName, err)
 		}