Empty values returned when pruned height is queried

[V-Staykov]

Summary of Bug

When trying to query anything with a --height that is pruned, the return is a default response, i.e. empty values, rather than error, as it is documented it should. I've traced the problem to store/iavl/store.go and GetImmutable function. There if VersionExists returns false, an error is expected to be thrown, but instead it is nil.

I say error is expected to be returned because of the comment in store/rootmulti/store.go in CacheMultiStoreWithVersion where GetImmutable is called and before it the comment says:

// Attempt to lazy-load an already saved IAVL store version. If the
// version does not exist or is pruned, an error should be returned.

The problem code is this:

if !st.VersionExists(version) {
	return &Store{tree: &immutableTree{&iavl.ImmutableTree{}}}, nil
}

Version

cosmos-sdk v0.45.3

Steps to Reproduce

Query a node with noded q staking validators --height <pruned_height_number> for a pruned block. It is expected to throw error, but returns empty array of balances.

Example return for pruned block:
noded q staking validators --height 99

pagination:
  next_key: null
  total: "0"
validators: []