Step execution order after Branch is completed

**Describe the bug**
If there is a registered step after .Decide step in a workflow, flow of execution is not as expected. If you add step after .Decide step, that step is executed right after first step from one of the branches, and not after whole branch is completed. How can I continue workflow after .Decide step?

**To Reproduce**
Add Step after .Decide step and start the workflow.

```
var branch1 = builder.CreateBranch()
.StartWith()
.Input(step => step.Message, data => "hi from 1")
.Then()
.Input(step => step.Message, data => "bye from 1");

var branch2 = builder.CreateBranch()
.StartWith()
.Input(step => step.Message, data => "hi from 2")
.Then()
.Input(step => step.Message, data => "bye from 2");

builder
.StartWith()
.Decide(data => data.Value1)
.Branch((data, outcome) => data.Value1 == "one", branch1)
.Branch((data, outcome) => data.Value1 == "two", branch2)
.Then()
.Input(step => step.Message, data => "Should be executed at the end.");
```

**Expected behavior**
Expected behavior if data.Value1 is set to "two":
- Expected output:
```
Hello
hi from 2
bye from 2
Should be executed at the end.
```

- Actual output:
```
Hello
hi from 2
Should be executed at the end.
bye from 2
```

**Additional context**
Screenshots:



Reproduce the workflow from the issue using the Decide, Branch, and following Then steps, and trace the branch execution order. Done means the selected branch completes both PrintMessage steps before the final PrintMessage runs, matching the expected output.

Written by the indexing model from the issue text.