Log Message:
elixir: update to 1.16.2.

1. Enhancements

Elixir

    [Code] Emit :defmodule tracing event on module definition

Mix

    [Mix] Add Mix.install_project_dir/0
    [Mix] Add environment variable for reusing Mix.install/2 installation
    [Mix.SCM] Add Mix.SCM.delete/1

2. Bug fixes

Elixir

    [Code] Fix charlist formatting issue when a single-quoted charlist escapes a \ 
double-quote character
    [Path] Fix regression on how Path.relative_to/2 dealt with "." as input

IEx

    [IEx.Helpers] Discard mermaid fenced blocks from ansi docs

ExUnit

    [ExUnit] Properly compared pinned values when building diffs