Add preprovision.yml to release manifest

Summary: the new playbook added under yugabyte#7995 was missing in the release manifest

Test Plan: make sure the playbook is included in the release

Reviewers: wesley

Reviewed By: wesley

Differential Revision: https://phabricator.dev.yugabyte.com/D11313

managed/devops/yb_release_manifest.json

@@ -7,6 +7,7 @@
     "python_requirements_frozen.txt",
     "python3_requirements_frozen.txt",
     "python*_modules.tar.gz",
+    "preprovision.yml",
     "use_custom_ssh_port.yml",
     "yb-server-ctl.yml",
     "yb-server-provision.yml",