fix: Fix group simulations (#11347)

## Description

It seems like #10887 broke group simulations, fixing them here.



---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

- [x] 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
- [x] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [ ] 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 `!` in the type prefix if API or client breaking change
- [ ] 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/group/keeper/invariants.go

@@ -167,6 +167,7 @@ func GroupTotalWeightInvariantHelper(ctx sdk.Context, key storetypes.StoreKey, g
 			msg += fmt.Sprintf("error while returning group member iterator for group with ID %d\n%v\n", groupInfo.Id, err)
 			return msg, broken
 		}
+		defer memIt.Close()
 
 		for {
 			_, err = memIt.LoadNext(&groupMember)
@@ -184,7 +185,6 @@ func GroupTotalWeightInvariantHelper(ctx sdk.Context, key storetypes.StoreKey, g
 				return msg, broken
 			}
 		}
-		memIt.Close()
 
 		groupWeight, err := groupmath.NewNonNegativeDecFromString(groupInfo.GetTotalWeight())
 		if err != nil {

x/group/simulation/operations.go

@@ -67,7 +67,7 @@ const (
 	WeightMsgSubmitProposal                  = 90
 	WeightMsgVote                            = 90
 	WeightMsgExec                            = 90
-	WeightMsgLeaveGroup                      = 20
+	WeightMsgLeaveGroup                      = 5
 	WeightMsgUpdateGroupMetadata             = 5
 	WeightMsgUpdateGroupAdmin                = 5
 	WeightMsgUpdateGroupMembers              = 5
@@ -188,10 +188,6 @@ func WeightedOperations(
 			weightMsgCreateGroupPolicy,
 			SimulateMsgCreateGroupPolicy(ak, bk, k),
 		),
-		simulation.NewWeightedOperation(
-			weightMsgLeaveGroup,
-			SimulateMsgLeaveGroup(k, ak, bk),
-		),
 		simulation.NewWeightedOperation(
 			weightMsgCreateGroupWithPolicy,
 			SimulateMsgCreateGroupWithPolicy(ak, bk),
@@ -235,6 +231,10 @@ func WeightedOperations(
 			weightMsgUpdateGroupPolicyMetadata,
 			SimulateMsgUpdateGroupPolicyMetadata(ak, bk, k),
 		),
+		simulation.NewWeightedOperation(
+			weightMsgLeaveGroup,
+			SimulateMsgLeaveGroup(k, ak, bk),
+		),
 	}
 
 	return append(wPreCreateProposalOps, append(createProposalOps, wPostCreateProposalOps...)...)

x/group/simulation/operations_test.go

@@ -53,7 +53,6 @@ func (suite *SimTestSuite) TestWeightedOperations() {
 	}{
 		{simulation.WeightMsgCreateGroup, group.MsgCreateGroup{}.Route(), simulation.TypeMsgCreateGroup},
 		{simulation.WeightMsgCreateGroupPolicy, group.MsgCreateGroupPolicy{}.Route(), simulation.TypeMsgCreateGroupPolicy},
-		{simulation.WeightMsgLeaveGroup, group.MsgLeaveGroup{}.Route(), simulation.TypeMsgLeaveGroup},
 		{simulation.WeightMsgCreateGroupWithPolicy, group.MsgCreateGroupWithPolicy{}.Route(), simulation.TypeMsgCreateGroupWithPolicy},
 		{simulation.WeightMsgSubmitProposal, group.MsgSubmitProposal{}.Route(), simulation.TypeMsgSubmitProposal},
 		{simulation.WeightMsgSubmitProposal, group.MsgSubmitProposal{}.Route(), simulation.TypeMsgSubmitProposal},
@@ -66,6 +65,7 @@ func (suite *SimTestSuite) TestWeightedOperations() {
 		{simulation.WeightMsgUpdateGroupPolicyAdmin, group.MsgUpdateGroupPolicyAdmin{}.Route(), simulation.TypeMsgUpdateGroupPolicyAdmin},
 		{simulation.WeightMsgUpdateGroupPolicyDecisionPolicy, group.MsgUpdateGroupPolicyDecisionPolicy{}.Route(), simulation.TypeMsgUpdateGroupPolicyDecisionPolicy},
 		{simulation.WeightMsgUpdateGroupPolicyMetadata, group.MsgUpdateGroupPolicyMetadata{}.Route(), simulation.TypeMsgUpdateGroupPolicyMetadata},
+		{simulation.WeightMsgLeaveGroup, group.MsgLeaveGroup{}.Route(), simulation.TypeMsgLeaveGroup},
 	}
 
 	for i, w := range weightedOps {