[LyX/master] Remove unneeded method

[Juergen Spitzmueller]

commit cd5a88029c5a06ce0eb8b8f31bdeaf49fb7963b6
Author: Juergen Spitzmueller <spitz at lyx.org>
Date:   Mon Sep 18 11:36:16 2023 +0200

    Remove unneeded method
    
    which is also not available in Qt < 5.13, as it turns out.
---
 src/frontends/qt/TocWidget.cpp |    9 +++------
 1 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/src/frontends/qt/TocWidget.cpp b/src/frontends/qt/TocWidget.cpp
index 0770cf3..da6d4f3 100644
--- a/src/frontends/qt/TocWidget.cpp
+++ b/src/frontends/qt/TocWidget.cpp
@@ -637,12 +637,9 @@ void TocWidget::collapseAllOthers(int const depth)
 	for (int i = size - 1; i >= 0; i--) {
 		QModelIndex index = indices[i];
 		if (tocTV->isExpanded(index)
-		    && !isAncestor(index, tocTV->currentIndex())) {
-			if (depth < getItemDepth(index))
-				tocTV->collapse(index);
-			if (depth > 0 && index.parent() == QModelIndex())
-				tocTV->expandRecursively(index, depth - 1);
-		}
+		    && !isAncestor(index, tocTV->currentIndex())
+		    && depth < getItemDepth(index))
+			tocTV->collapse(index);
 	}
 }