Remove arrow key test

We aren't implementing this behavior anymore (it's the default with
QTreeView), so we don't need to test it.

tests/widgets/test_result_tree.py

@@ -96,28 +96,11 @@ def test_arrow_key_expansion(fixed_tree: SearcherTreeView, qtbot, asserter):
  idx = fixed_tree.model().index(0, 0)
  fixed_tree.setCurrentIndex(idx)
  expanded = fixed_tree.isExpanded(idx)
- # Part 1: toggle with Enter
+ # Toggle with enter
  qtbot.keyPress(fixed_tree, Qt.Key_Return)
  assert fixed_tree.isExpanded(idx) is not expanded
  qtbot.keyPress(fixed_tree, Qt.Key_Return)
  assert fixed_tree.isExpanded(idx) is expanded
- # Part 2: test arrow keys
- fixed_tree.setExpanded(idx, True)
- # Part 2.1: Expanded + Left hides children
- qtbot.keyPress(fixed_tree, Qt.Key_Left)
- assert fixed_tree.isExpanded(idx) is False
- # Part 2.2: Hidden + Right shows children
- qtbot.keyPress(fixed_tree, Qt.Key_Right)
- assert fixed_tree.isExpanded(idx) is True
- # Part 2.3: Expanded + Right selects first child
- qtbot.keyPress(fixed_tree, Qt.Key_Right)
- asserter(
- lambda: fixed_tree.currentIndex().row() == 0
- and fixed_tree.currentIndex().parent() == idx
- )
- # Part 2.4: Child + Left returns to parent
- qtbot.keyPress(fixed_tree, Qt.Key_Left)
- asserter(lambda: fixed_tree.currentIndex() == idx)
 
 
 def test_search_tree_disable(fixed_tree: SearcherTreeView, asserter):