bug#35055: 27.0.50; async-shell-command truncates output lines

[Juri Linkov]

Test case:

1. Open a wide frame and type:

2. `M-& ps aux RET'

3. observe that output lines are truncated at column 80

Another example: `M-& dpkg -l '*emacs*' RET', then try to copy
full package names from the *Async Shell Command* buffer.
Nope, it's impossible because they are truncated.

OTOH, there is no such problem with `M-! ps aux RET'
where lines are not truncated at all.

So the question is: why `M-&' (async-shell-command) limits COLUMNS to 80,
even on wide frames, whereas `M-!' (shell-command) has no limitation.

A third case is `M-x shell' that limits COLUMNS to window-width,
but at least it makes possible to change the window width (e.g.
to make it wider) to influence the number of output columns.