guild.mod: make execute prune blockable on prune result

litecord/blueprints/guild/mod.py

@@ -201,5 +201,8 @@ async def begin_guild_prune(guild_id):
     days = j["days"]
     member_ids = await get_prune(guild_id, days)
 
-    app.sched.spawn(prune_members(user_id, guild_id, member_ids))
+    # TODO move this job to the background scheduler in a way
+    # that the test can fetch the job and wait on it before
+    # asserting test result state
+    await prune_members(user_id, guild_id, member_ids)
     return jsonify({"pruned": len(member_ids)})