Merge pull request #2161 from AleoHQ/fix/reward-truncation-and-overflow

[TOB] Remove possible truncation in `block_reward`

Author: howardwu

ledger/block/src/helpers/target.rs

@@ -27,7 +27,7 @@ pub const fn block_reward(total_supply: u64, block_time: u16, coinbase_reward: u
     // Compute the expected block height at year 1.
     let block_height_at_year_1 = block_height_at_year(block_time, 1);
     // Compute the annual reward: (0.05 * S).
-    let annual_reward = (total_supply / 1000) * 50;
+    let annual_reward = total_supply / 20;
     // Compute the block reward: (0.05 * S) / H_Y1.
     let block_reward = annual_reward / block_height_at_year_1 as u64;
     // Return the sum of the block reward, coinbase reward, and transaction fees.