Fix reward error and upgrade to gemini-3g-2024-jan-08 snapshot

[ParthDesai]

Description

This PR fixes the error encountered during the decoding of the events. And also upgrades to gemini-3g-2024-jan-08 snapshot.

Context

During the gemini-3g network run, we upgraded the runtime multiple times. During one of the upgrade, we modified FraudProofProcessed event. Specifically, adding Option to the new_head_receipt_number field. This added an extra byte in the encoding of that event after the runtime upgrade.

Issue

Since pulsar uses the latest runtime present in the code (and not on-chain runtime for that block) to decode the events, when it encounters the FraudProofProcessed event generated before runtime upgrade, it reads one extra byte during the decoding. This causes the decoding of next runtime event to fail and since the EventPhase is the first field in an event, the decoding of it fails with the variant does not exists error.

Solution

Three potential solutions were investigated:

1. Use runtime at particular block to decode the event (Rejected: Too costly and complex to implement in order to simply count the votes and rewards)
2. Modify subspace runtime to return votes and rewards at particular block (Rejected: Would require refactoring runtime just to accommodate pulsar)
3. Remove votes and rewards data aggregation from pulsar (Accepted: This is ideal solution since it would not require introduction of more machinery and votes and rewards data are now viewed from the subspace block explorer as well.)

3rd solution is and implemented in this PR by removing calculation of votes and rewards from pulsar. If at any point of time, subspace runtime do introduce the functionality to query the votes and rewards through runtime api or rpc for particular block, this can be revisited.