fix: use min delegation for SubgraphService tests (#1080)

Author: Maikol

Diff for: packages/subgraph-service/test/shared/SubgraphServiceShared.t.sol

@@ -41,7 +41,7 @@ abstract contract SubgraphServiceSharedTest is HorizonStakingSharedTest {
     }
 
     modifier useDelegation(uint256 tokens) {
-        vm.assume(tokens > 1);
+        vm.assume(tokens > MIN_DELEGATION);
         vm.assume(tokens < 10_000_000_000 ether);
         (, address msgSender,) = vm.readCallers();
         resetPrank(users.delegator);

Diff for: packages/subgraph-service/test/utils/Constants.sol

@@ -20,6 +20,7 @@ abstract contract Constants {
     uint256 public constant curationCut = 10000;
     // Staking
     uint64 internal constant MAX_WAIT_PERIOD = 28 days;
+    uint256 internal constant MIN_DELEGATION = 1 ether;
     // GraphEscrow parameters
     uint256 internal constant withdrawEscrowThawingPeriod = 60;
     // GraphPayments parameters