Displayed widgets instances from the same workgraph are not independent

A notebook of the form
Cell 1
```python
def sleep_and_print(sleep_time, print_statement):
    time.sleep(sleep_time)
    print(print_statement)

wg = WorkGraph('First WG')

wg.add_task(sleep_and_print)
wg
```
Cell 2
```python
wg.add_task(sleep_and_print)
wg
```
The widget instance in the cell 1 is affected by the action in cell 2

Workaround use `wg.to_hmtl()`