Gantt - Testcafe: skip a11y errors in flaky "Gantt-Overview" demo test (#32956)

Signed-off-by: Danil Mirgaev <danil.mirgaev@devexpress.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: dmirgaev

apps/demos/testing/common.test.ts

@@ -105,6 +105,7 @@ const getIgnoredRules = (testName) => {
 
     'Gantt-Appearance': ['aria-toggle-field-name'],
     'Gantt-ExportToPDF': ['aria-toggle-field-name'],
+    'Gantt-Overview': ['aria-required-parent', 'aria-valid-attr-value'],
     'Gantt-StripLines': ['aria-required-parent', 'aria-valid-attr-value'],
     'Gantt-Validation': ['aria-required-parent', 'aria-valid-attr-value'],