refactor: Get last execution and find last internal ID

packages/backend/src/models/flow.ts

@@ -4,6 +4,7 @@ import Base from './base';
 import Step from './step';
 import Execution from './execution';
 import Telemetry from '../helpers/telemetry';
+import { IExecution } from '@automatisch/types';
 
 class Flow extends Base {
   id!: string;
@@ -50,11 +51,11 @@ class Flow extends Base {
   });
 
   async lastInternalId() {
-    const lastInternalIdFetched: any = await this.$relatedQuery(
-      'executions'
-    ).max('internal_id');
+    const lastExecution = await this.$relatedQuery('executions')
+      .orderBy('created_at', 'desc')
+      .first();
 
-    return lastInternalIdFetched[0].max;
+    return (lastExecution as Execution).internalId;
   }
 
   async $beforeUpdate(