convert QTreeWidget.setFirstItemColumnSpanned

convert QTreeWidget.setFirstItemColumnSpanned(item, True) to
item.setFirstColumnSpanned(True)

the former is deprecated since Qt 5.15.2 and removed in Qt 6.

pyqtgraph/parametertree/parameterTypes.py

@@ -429,11 +429,11 @@ class GroupParameterItem(ParameterItem):
         tw = self.treeWidget()
         if tw is None:
             return
-        tw.setFirstItemColumnSpanned(self, True)
+        self.setFirstColumnSpanned(True)
         if self.addItem is not None:
             tw.setItemWidget(self.addItem, 0, self.addWidgetBox)
-            tw.setFirstItemColumnSpanned(self.addItem, True)
-        
+            self.addItem.setFirstColumnSpanned(True)
+
     def addChild(self, child):  ## make sure added childs are actually inserted before add btn
         if self.addItem is not None:
             ParameterItem.insertChild(self, self.childCount()-1, child)
@@ -609,7 +609,7 @@ class ActionParameterItem(ParameterItem):
         if tree is None:
             return
         
-        tree.setFirstItemColumnSpanned(self, True)
+        self.setFirstColumnSpanned(True)
         tree.setItemWidget(self, 0, self.layoutWidget)
 
     def titleChanged(self):
@@ -646,7 +646,7 @@ class TextParameterItem(WidgetParameterItem):
         if tw is None:
             return
 
-        tw.setFirstItemColumnSpanned(self.subItem, True)
+        self.subItem.setFirstColumnSpanned(True)
         tw.setItemWidget(self.subItem, 0, self.textBox)
         
         # for now, these are copied from ParameterItem.treeWidgetChanged

pyqtgraph/widgets/DataTreeWidget.py

@@ -65,7 +65,7 @@ class DataTreeWidget(QtGui.QTreeWidget):
             subnode = QtGui.QTreeWidgetItem(["", "", ""])
             node.addChild(subnode)
             self.setItemWidget(subnode, 0, widget)
-            self.setFirstItemColumnSpanned(subnode, True)
+            subnode.setFirstColumnSpanned(True)
             
         # recurse to children
         for key, data in childs.items():