Dispatch "post-package-update" event after writing lock (#7766)

Fixes #7765

src/Composer/Installer.php

@@ -610,14 +610,14 @@ class Installer
                 }
             }
 
+            if ($this->executeOperations || $this->writeLock) {
+                $localRepo->write();
+            }
+
             $event = 'Composer\Installer\PackageEvents::POST_PACKAGE_'.strtoupper($jobType);
             if (defined($event) && $this->runScripts) {
                 $this->eventDispatcher->dispatchPackageEvent(constant($event), $this->devMode, $policy, $pool, $installedRepo, $request, $operations, $operation);
             }
-
-            if ($this->executeOperations || $this->writeLock) {
-                $localRepo->write();
-            }
         }
 
         if ($this->executeOperations) {