bug#53501: 29.0.50; Column widening widens multiple columns in *Process List*

[Thuna]

In the *Porcess List* buffer, if tabulated-list-widen-column is called
on the second or the third column, both columns end up widening.  The
same thing happens in columns 5 and 6 as well (although it is currently
bugged due to bug#53498).

This can be replicated as follows:
0. emacs -Q
1. M-x shell
2. M-x list-processes
3. C-x o
4. M-f M-f
5. }

It is possible that this is not a bug in process itself but I have seen
nothing else that could be the problem.