TargetWorkspaceSelectorWidget Fix (SeequentEvo#167)

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## Description

A simple fix to display the appropriate selected source workspace name
under TargetWorkspaceSelectorWidget.

## Checklist

- [x] I have read the contributing guide and the code of conduct

Author: shivangj10

samples/workspaces/bonus/workspace_utils.py

@@ -218,7 +218,13 @@ class TargetWorkspaceSelectorWidget:
 
     def __init__(self, manager_widget):
         self.manager_widget = manager_widget
-        self.current_workspace_id = manager_widget.workspaces[0].id if manager_widget.workspaces else None
+        # Get the selected workspace ID
+        selected_id = manager_widget._workspace_selector.selected
+
+        if selected_id != manager_widget._workspace_selector.UNSELECTED[1]:
+            self.current_workspace_id = selected_id
+        else:
+            raise ValueError("No source workspace is currently selected.")
 
         # Create widgets
         self.refresh_btn = widgets.Button(