Editor: Cannot remove numbered list

[ericvicenti]

Repro: create a numbered list inside a block in the editor

1. When the cursor is at the beginning of the line, "delete" should remove the numbered list. Instead it removes the newline
2. The Turn into... > Paragraph menu does nothing

[iskaktoltay]

https://github.com/MintterHypermedia/mintter/assets/36269035/8921d9fb-6461-4261-9ad8-a41bf981fa4d
Delete works fine for me @ericvicenti