fix: RewardBallotWinners determinism (#1433)

## Description

Fixes RC1 Canon consensus failure.

Bug was in: https://github.com/umee-network/umee/pull/1433/files#diff-971aeedb004816fd5770d86dfa2d9ee39c5e53d7802773dd9e81cbc2cf890f62L60

---

### Author Checklist

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please add links to any relevant follow up issues._

I have...

- [ ] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [ ] added appropriate labels to the PR
- [ ] targeted the correct branch (see [PR Targeting](https://github.com/umee-network/umee/blob/main/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [ ] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

_All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items._

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed all author checklist items have been addressed
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

x/oracle/abci.go

@@ -77,7 +77,7 @@ func EndBlocker(ctx sdk.Context, k keeper.Keeper) error {
 			int64(params.VotePeriod),
 			int64(params.RewardDistributionWindow),
 			voteTargetDenoms,
-			validatorClaimMap,
+			claimSlice,
 		)
 
 		// Clear the ballot

x/oracle/keeper/reward.go

@@ -16,7 +16,7 @@ func (k Keeper) RewardBallotWinners(
 	votePeriod int64,
 	rewardDistributionWindow int64,
 	voteTargets []string,
-	ballotWinners map[string]types.Claim,
+	ballotWinners []types.Claim,
 ) {
 	rewardDenoms := make([]string, len(voteTargets)+1)
 	rewardDenoms[0] = types.UmeeDenom
@@ -57,6 +57,7 @@ func (k Keeper) RewardBallotWinners(
 
 	// distribute rewards
 	var distributedReward sdk.Coins
+
 	for _, winner := range ballotWinners {
 		receiverVal := k.StakingKeeper.Validator(ctx, winner.Recipient)
 		// in case absence of the validator, we just skip distribution

x/oracle/keeper/reward_test.go

@@ -9,9 +9,9 @@ import (
 // Test the reward giving mechanism
 func (s *IntegrationTestSuite) TestRewardBallotWinners() {
 	// Add claim pools
-	claims := map[string]types.Claim{
-		valAddr.String():  types.NewClaim(10, 10, 0, valAddr),
-		valAddr2.String(): types.NewClaim(20, 20, 0, valAddr2),
+	claims := []types.Claim{
+		types.NewClaim(10, 10, 0, valAddr),
+		types.NewClaim(20, 20, 0, valAddr2),
 	}
 
 	// Prepare reward pool
@@ -38,7 +38,8 @@ func (s *IntegrationTestSuite) TestRewardBallotWinners() {
 }
 
 func (s *IntegrationTestSuite) TestRewardBallotWinnersZeroPower() {
-	s.app.OracleKeeper.RewardBallotWinners(s.ctx, 0, 0, []string{}, map[string]types.Claim{valAddr.String(): {}})
+	zeroClaim := types.NewClaim(0, 0, 0, valAddr)
+	s.app.OracleKeeper.RewardBallotWinners(s.ctx, 0, 0, []string{}, []types.Claim{zeroClaim})
 	outstandingRewardsDec := s.app.DistrKeeper.GetValidatorOutstandingRewardsCoins(s.ctx, valAddr)
 	s.Require().Equal("", outstandingRewardsDec.String())
 }