L1 expiration should not touch stores or other nodes

When L1 entries expire, they use the same expiration logic that regular lifespan expiration uses.

But L1 entries are only stored in the data container, and the lifespan is different on each node, so L1 entry expiration should be a lot less expensive than regular lifespan expiration.

We also need a test for L1 expiration in the core test suite. Regular lifespan expiration tests were probably enough before lifespan expiration became clustered, but L1 is different enough that it should have its own tests.