don't force latest elixir (fix for nixos 24.11)

mix.exs

@@ -5,7 +5,7 @@ defmodule SpindleyBot.MixProject do
     [
       app: :spindleybot,
       version: "0.1.0",
-      elixir: "~> 1.18",
+      elixir: "~> 1.17",
       start_permanent: Mix.env() == :prod,
       deps: deps()
     ]
@@ -27,9 +27,6 @@ defmodule SpindleyBot.MixProject do
       {:nostrum, "~> 0.10"},
       {:dotenvy, "~> 1.0.0"},
       {:req, "~> 0.5.0"}
-
-      # {:dep_from_hexpm, "~> 0.3.0"},
-      # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
     ]
   end
 end