deprecation-workflow: Remove obsolete ember-data:model-save-promise config

It looks like Ember Data has been fixed to no longer warn about this, so we can remove the deprecation silencing behavior.

Author: Turbo87

config/deprecation-workflow.js

@@ -2,9 +2,5 @@
 
 self.deprecationWorkflow = self.deprecationWorkflow || {};
 self.deprecationWorkflow.config = {
-  workflow: [
-    // disabled because it's a false positive caused by ember-concurrency
-    // checking if `__ec_cancel__` is available.
-    { handler: 'silence', matchId: 'ember-data:model-save-promise' },
-  ],
+  workflow: [],
 };