fix: address tmnt 157 (#16457)

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Author: LHerskind

l1-contracts/gas_benchmark.md

@@ -65,7 +65,7 @@
 |----------------------|---------|---------|---------------|--------------|
 | propose              | 334,960 | 352,320 |         4,580 |       73,280 |
 | submitEpochRootProof | 895,025 | 933,081 |         6,308 |      100,928 |
-| aggregate3           | 373,091 | 390,443 |             - |            - |
+| aggregate3           | 373,092 | 390,455 |             - |            - |
 | setupEpoch           |  49,728 | 542,190 |             - |            - |
 
 **Avg Gas Cost per Second**: 10,901.5 gas/second

l1-contracts/gas_benchmark_results.json

@@ -55,9 +55,9 @@
       },
       "aggregate3": {
         "calls": 100,
-        "min": 239389,
+        "min": 239377,
         "mean": 245657,
-        "median": 245991,
+        "median": 245997,
         "max": 265021
       }
     }
@@ -118,10 +118,10 @@
       },
       "aggregate3": {
         "calls": 100,
-        "min": 357506,
-        "mean": 373091,
-        "median": 373535,
-        "max": 390443
+        "min": 357518,
+        "mean": 373092,
+        "median": 373541,
+        "max": 390455
       }
     }
   }

l1-contracts/src/governance/GSE.sol

@@ -661,8 +661,9 @@ contract GSE is IGSE, GSECore {
   /**
    * @notice  Get the effective balance of the attester at the instance.
    *
-   *          The effective balance is the balance of the attester at the instance,
-   *          plus the balance of the attester at the bonus instance if the instance is the latest rollup.
+   *          The effective balance is the balance of the attester at the specific instance or at the bonus if the
+   *          instance is the latest rollup and he was not at the specific. We can do this as an `or` since the
+   *          attester may only be active at one of them.
    *
    * @param _instance   - The instance to look at
    * @param _attester   - The attester to look at
@@ -671,8 +672,8 @@ contract GSE is IGSE, GSECore {
    */
   function effectiveBalanceOf(address _instance, address _attester) external view override(IGSE) returns (uint256) {
     uint256 balance = delegation.getBalanceOf(_instance, _attester);
-    if (getLatestRollup() == _instance) {
-      balance += delegation.getBalanceOf(BONUS_INSTANCE_ADDRESS, _attester);
+    if (balance == 0 && getLatestRollup() == _instance) {
+      return delegation.getBalanceOf(BONUS_INSTANCE_ADDRESS, _attester);
     }
     return balance;
   }