fix(list-keymap): prevent selection deletions at the end of list items from joining lists (#5863)

If starting a selection at the end of a list item, then pressing delete, the selected text wasn't being deleted, but instead the following list item was joined to the end.

Now the selected text will be deleted.

Joining will only occur if the selection spans multiple nodes or it's collapsed.

.changeset/four-islands-chew.md

@@ -0,0 +1,5 @@
+---
+"@tiptap/extension-list-keymap": patch
+---
+
+Improve selected text deletion at the end of list items

packages/extension-list-keymap/src/listHelpers/handleDelete.ts

@@ -16,6 +16,15 @@ export const handleDelete = (editor: Editor, name: string) => {
     return false
   }
 
+  // if the selection is not collapsed, or not within a single node
+  // do nothing and proceed
+  const { selection } = editor.state
+  const { $from, $to } = selection
+
+  if (!selection.empty && $from.sameParent($to)) {
+    return false
+  }
+
   // check if the next node is a list with a deeper depth
   if (nextListIsDeeper(name, editor.state)) {
     return editor