`juvix format` breaks `else` clause in multiway if syntax

[paulcadman]

Reproduced using the latest nightly build.

This bug was introduced since the 0.6.3 release, possibly in https://github.com/anoma/juvix/pull/2852

Consider a module that contains multiway if syntax:

module Bug;

import Stdlib.Prelude open;

a : Nat :=
  if
    | true := 1
    | else := 2;

and run juvix format --inplace, the following is the result:

module Bug;

import Stdlib.Prelude open;

a : Nat :=
  if
    | true := 1
    else := 2;

and this does not typecheck:

$ juvix typecheck Bug.juvix
/private/tmp/Bug.juvix:8:9: error:
/private/tmp/Bug.juvix:8:9:
  |
8 |     else := 2;
  |         ^
expecting |