Add navigation handling for agent deletion confirmation modal

This update modifies the agent deletion confirmation modal to prevent navigation back when the modal is displayed, ensuring a smoother user experience during the deletion process.

Author: NicolasBonet

src/pages/settings/Agents/EditAgentPage.tsx

@@ -47,6 +47,7 @@ function EditAgentPage({route}: EditAgentPageProps) {
             confirmText: translate('common.delete'),
             cancelText: translate('common.cancel'),
             danger: true,
+            shouldHandleNavigationBack: false,
         });
         if (result.action !== ModalActions.CONFIRM) {
             return;