Update required Elixir version

Author: varsill

CHANGELOG.md

@@ -5,6 +5,7 @@
 * Deprecate `:components` option for `:unsafely_name_processes_for_observer`
 * Deprecate `:links` option for `:unsafely_name_processes_for_observer` in favour of `:report_links_to_observer` configuration entry
 * [Set label](https://hexdocs.pm/elixir/Process.html#set_label/1) for all the Membrane processes (i.e. for both Membrane components like pipelines, elements and bins and for utility components like subprocess supervisors)
+* Update required Elixir version to `~> 1.17`
 
 ## 1.2.6
  * Add tutorials [#1007](https://github.com/membraneframework/membrane_core/pull/1007), plugins [#1012](https://github.com/membraneframework/membrane_core/pull/1012) and demos [#1013](https://github.com/membraneframework/membrane_core/pull/1013) to the docs.

mix.exs

@@ -9,7 +9,7 @@ defmodule Membrane.Mixfile do
     [
       app: :membrane_core,
       version: @version,
-      elixir: "~> 1.12",
+      elixir: "~> 1.17",
       elixirc_paths: elixirc_paths(Mix.env()),
       description: "Membrane Multimedia Framework (Core)",
       dialyzer: dialyzer(),