The indent guide computation was using visible list indices directly to
access entries, instead of mapping through `logical_indices` first. This
caused incorrect depths to be read from hidden entries when a folder was
collapsed, resulting in stray vertical lines extending to unrelated folders.
Closes#48189
Release Notes:
- Fixed a visual bug in the Git Panel where collapsing a folder in tree
view would cause indent guide lines to incorrectly extend to unrelated
folders below it.