Fix container libEGL collection error and suppress Sonar slice false-positive

- test_script_builder_param_preservation: importorskip PySide6.QtWidgets (not
  the bare PySide6 package) so it skips when Qt runtime libs like libEGL.so.1
  are absent — the shipped Docker image lacks them, so importing QtWidgets
  aborted collection of the whole in-image suite.
- test_platform_backend_binding: NOSONAR the slice assertion Sonar keeps
  flagging as S6466; a slice cannot raise IndexError, so it is a false positive.

Author: JE-Chen

test/unit_test/headless/test_platform_backend_binding.py

@@ -161,7 +161,7 @@ def test_scroll_clamps_and_fills_a_partial_coordinate(monkeypatch):
 
     auto_control_mouse.mouse_scroll(5, x=99999)
 
-    assert events[:1] == [("move", 1919, 7)]
+    assert events[:1] == [("move", 1919, 7)]  # NOSONAR python:S6466  # reason: slice, not index — cannot raise IndexError
 
 
 def test_missing_coords_still_fall_back_to_the_cursor(monkeypatch):

test/unit_test/headless/test_script_builder_param_preservation.py

@@ -6,7 +6,7 @@
 """
 import pytest
 
-pytest.importorskip("PySide6")
+pytest.importorskip("PySide6.QtWidgets")  # skips if Qt libs (e.g. libEGL) absent
 
 from PySide6.QtWidgets import QApplication  # noqa: E402