lang/elixir: update to 1.7.4.

1. Enhancements

Elixir

    [Kernel] Expand left..right at compile time in more cases, which leads to improved performance under different scenarios, especially on x in left..right expressions

Mix

    [mix deps.loadpaths] Add --no-load-deps flag. This is useful for Rebar 3 compatibility

2. Bug fixes

Elixir

    [Calendar] Fix for converting from negative iso days on New Year in a leap year
    [Kernel] Ensure @spec, @callback, @type and friends can be read accordingly
    [Module] Avoid warnings when using Module.eval_quoted in the middle of existing definitions

Mix

    [mix archive.build] Unload previous archive versions before building
    [mix format] Expand paths so mix format path\for\windows.ex works
    [mix test] Ensure that --cover displays correct coverage in an umbrella app

(nia)