Miss balances ssz cache in state transition

[twoeths]

Describe the bug

In every epoch transition, we create balances tree from a list of number[] and the resulting ViewDU does not contain any cached nodes https://github.com/ChainSafe/lodestar/blob/36f50cf08337e70b0f8078949a23162256ec03a2/packages/state-transition/src/epoch/processRewardsAndPenalties.ts#L36C40-L36C48

If we have balances cached nodes we can:

• process blocks faster
• with n-historical state work, we serialize() the state faster, see feat: improve ViewDU.serialize() ssz#350

this issue is shown in lodestar nodes:

Expected behavior

Retain balances ssz cache after we create balances

Steps to reproduce

No response

Additional context

No response

Operating system

Linux

Lodestar version or commit hash

unstable