Fix datetime precision regression from Timex.shift/2

[emancu]

In Elixir 1.14+, Timex.shift/2 upgrades datetime precision to microseconds due to changes in DateTime.add/4.

This caused date_and_offset_to_datetime/3 to return datetimes like ~U[2023-01-01 10:00:00.000000Z] instead of ~U[2023-01-01 10:00:00Z], breaking Ecto validations and equality checks.

Fix: truncate to :second precision after shift since input is always ~T[00:00:00] (second precision).

Also updates all dependencies to latest compatible versions.

Is it the same fix as the fork?

No. The fork preserves the original precision dynamically:

  # Fork approach - general purpose
  defp retain_precision(new_datetime, original_datetime) do
    precision = original_datetime.microsecond |> elem(1)
    %{new_datetime | microsecond: {elem(new_datetime.microsecond, 0), precision}}
  end

My fix hardcodes :second truncation:

  # Surgex approach - specific to this function
  NaiveDateTime.truncate(shifted, :second)

Ref: bitwalker/timex#731

⚠️ By mistake, the fix was merged with fixing the pipelines... see here

[emancu]

Waiting for #61