Add missing calendar key to Calendar.time() and fix truncate spec (#15572)

Author: lukaszsamson

lib/elixir/lib/calendar.ex

@@ -106,6 +106,7 @@ defmodule Calendar do
   @typedoc "Any map or struct that contains the time fields."
   @type time :: %{
           optional(any) => any,
+          calendar: calendar,
           hour: hour,
           minute: minute,
           second: second,

lib/elixir/lib/calendar/naive_datetime.ex

@@ -672,7 +672,7 @@ defmodule NaiveDateTime do
 
   """
   @doc since: "1.6.0"
-  @spec truncate(t(), :microsecond | :millisecond | :second) :: t()
+  @spec truncate(Calendar.naive_datetime(), :microsecond | :millisecond | :second) :: t()
   def truncate(%NaiveDateTime{microsecond: microsecond} = naive_datetime, precision) do
     %{naive_datetime | microsecond: Calendar.truncate(microsecond, precision)}
   end