PyQt6: QBoxLayout.setAlignment(Qt.AlignmentFlag) raises TypeError

[Ales Erjavec]

Hi,

Trying to set an alignment on a QBoxLayout raises a TypeError:
```
from PyQt6.QtCore import Qt
from PyQt6.QtWidgets import QApplication, QWidget, QHBoxLayout

app = QApplication([])

lay = QHBoxLayout()
lay.setAlignment(Qt.AlignmentFlag.AlignLeft)   # << error
```

The error:
```
TypeError: arguments did not match any overloaded call:
  setAlignment(self, QWidget, Qt.AlignmentFlag): argument 1 has
unexpected type 'AlignmentFlag'
  setAlignment(self, QLayout, Qt.AlignmentFlag): argument 1 has
unexpected type 'AlignmentFlag'
```
The two listed overloads are from QLayout implementation but the
intended call is for
the base QLayoutItem.setAlignment.

In PyQt5 this worked as evident by the QHBoxLayout.setAlignment docstring:
```
setAlignment(self, QWidget, Union[Qt.Alignment, Qt.AlignmentFlag]) -> bool
setAlignment(self, QLayout, Union[Qt.Alignment, Qt.AlignmentFlag]) -> bool
setAlignment(self, Union[Qt.Alignment, Qt.AlignmentFlag])
```

Best wishes
Aleš Erjavec