Describe the bug

After a cell is deleted or a variable is even just declared in a cell, I cannot move that variable declaration to a different cell

Steps:

1. Create and run cell with x = 4
2. Delete cell
3. Create and run new cell with x = 3

Error:

This cell wasn't run because it has errors
The variable 'x' was defined by another cell:

Tip:
Try merging this cell with the above cells. Alternatively, rename 'x' to '_x' to make the variable private to this cell.

(Side note, I don't think merging cells is a thing right now right? Tried searching the docs)

I can see the use of private variables as being good practice to do generally, but when a cell is deleted it would still be nice to be able to free up that variable for redeclaration.

I ran into this when I was simply trying to reorganize my notebook a bit.

Environment

(was just reproducing on marimo.app)

Code to reproduce

No response