This was discovered while investigating BF-24415

In commands.cpp, CommandHelpers::runCommandInvocation, we do:

auto hooks = getCommandInvocationHooksHandle(opCtx->getServiceContext());

Given that the ServiceContext keeps keeps the CommandInvocationHooks alive, there is no need for hooks to be a shared_ptr. getCommandInvocationHooksHandle should not cause us to Incref and Decref. 

We don't expect for this to address the root cause of BF-BF-24415, but we do expect it to manifest more clearly if we introduce this change.