Fixes rewards not calculated correctly

[ibraheem-opentensor]

Previously, the rewards were not being calculated correctly:

• Validators calculate rewards of miners.
• The uids that the template fetches includes both miners & validators.
• Validators do not mine, hence we get None in their response for challenge/queries
• We were removing the None responses which created discrepancy in update_scores. UIDs are 6 but rewards calculated are 3.
• The rewards calculated should also be 6, with 0 values for validator uids and 1 for miners.

TLDR: Reverts community PR: https://github.com/opentensor/bittensor-subnet-template/commit/1e312a2ed53be6cd14179f4d3f2b502d6545d1e0#diff-49d9ab1edc3e8d10c4a1f67459ae714c20b3072cb2624b56d01b32339cace4c6