[FIX] account: removed horizontal scrollbar in lists

Before this commit, lists having a section or a note would have a horizontal
scrollbar in readonly mode.

Now it has been removed and the list stretches properly according to its parent
size.

Task 2086594

closes odoo/odoo#38113

Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>

addons/account/static/src/scss/section_and_note_backend.scss

@@ -16,3 +16,14 @@ table.o_section_and_note_list_view tr.o_data_row.o_is_line_section {
     border-top: 1px solid #BBB;
     border-bottom: 1px solid #BBB;
 }
+
+table.o_section_and_note_list_view tr.o_data_row {
+    &.o_is_line_note,
+    &.o_is_line_section {
+        td {
+            // There is an undeterministic CSS behaviour in Chrome related to
+            // the combination of the row's and its children's borders.
+            border: none !important;
+        }
+    }
+}