chore(xo-server/snapshotVm): avoid using waitObjectState

packages/xo-server/src/xapi/index.js

@@ -1442,8 +1442,6 @@ export default class Xapi extends XapiBase {
         nameLabel
       ).then(extractOpaqueRef)
       this.addTag(ref, 'quiesce')::ignoreErrors()
-
-      await this._waitObjectState(ref, vm => includes(vm.tags, 'quiesce'))
     } catch (error) {
       const { code } = error
       if (
@@ -1467,7 +1465,7 @@ export default class Xapi extends XapiBase {
     // to-date object.
     const [, snapshot] = await Promise.all([
       this.call('VM.set_is_a_template', ref, false),
-      this._waitObjectState(ref, snapshot => !snapshot.is_a_template),
+      this.barrier(ref),
     ])
 
     return snapshot