When APIs are deleted, delete any deployments that they own. (#395)

(This is for consistency with existing behavior. In the future we will block deletion of objects when children exist unless a `force` argument is present and true.)

server/registry/internal/storage/apis.go

@@ -159,6 +159,8 @@ func (d *Client) DeleteApi(ctx context.Context, name names.Api) error {
 		gorm.VersionEntityName,
 		gorm.SpecEntityName,
 		gorm.SpecRevisionTagEntityName,
+		gorm.DeploymentEntityName,
+		gorm.DeploymentRevisionTagEntityName,
 		gorm.ArtifactEntityName,
 		gorm.BlobEntityName,
 	} {