Conversion of quint Map.setBy produces invalid Apalache IR

[shonfeder]

The expression m.setBy(n, x => x + 1).get(n) == nextN produces Apalache IR like

    /\ LET (*@type: (() => (Int -> Int)); *) __quint_var3 == m IN
    [
      (__quint_var3) EXCEPT
        ![n] =
          (LET (*@type: ((Int) => Int); *) __QUINT_LAMBDA0(x) == x + 1 IN
          __QUINT_LAMBDA0)((__quint_var3)[n])
    ][
      n
    ]
      = nextN

And this yields the error

    at.forsyte.apalache.infra.AdaptedException: <unknown>: internal error in type checking: Bug in ToEtcExpr. Expected an operator name, found: LET __QUINT_LAMBDA0(x) ≜ x + 1 IN __QUINT_LAMBDA0

Which is another instance of running in to #2517