Run integrity on release postbump

buildutils/src/utils.ts

@@ -1,6 +1,9 @@
 import { getPythonVersion, run } from '@jupyterlab/buildutils';
 
 export function postbump(): void {
+  // run the integrity
+  run('jlpm integrity');
+
   const newPyVersion = getPythonVersion();
   // Commit changes.
   run(`git commit -am "Release ${newPyVersion}"`);