Fix typings on config modules

lib/last_fm/config.ex

@@ -46,7 +46,7 @@ defmodule LastFm.Config do
           )
 
   @doc NimbleOptions.docs(@schema)
-  @spec resolve(atom) :: t
+  @spec resolve(atom) :: t | no_return
   def resolve(otp_app) do
     app_config =
       Application.get_env(otp_app, LastFm)

lib/music_brainz/config.ex

@@ -20,7 +20,7 @@ defmodule MusicBrainz.Config do
           )
 
   @doc NimbleOptions.docs(@schema)
-  @spec resolve(atom) :: t
+  @spec resolve(atom) :: t | no_return
   def resolve(otp_app) do
     app_config =
       Application.get_env(otp_app, MusicBrainz)