The vault instances lose the raft leader status, while loading
the `vault-auth-tee` plugin, because the gramine enviroment slows
down the `execve` significantly.
Using `performance_multiplier` relaxes the timeouts for the raft protocol.
see also: https://github.com/hashicorp/vault/issues/28009
Signed-off-by: Harald Hoyer <harald@matterlabs.dev>