Revert "Pleroma.Web.PleromaAPI.ChatController: Dialyzer error"

This reverts commit 8d64eedbec.

lib/pleroma/web/api_spec/operations/chat_operation.ex

@@ -378,9 +378,9 @@ def mark_as_read do
       title: "MarkAsReadRequest",
       description: "POST body for marking a number of chat messages as read",
       type: :object,
-      required: ["last_read_id"],
+      required: [:last_read_id],
       properties: %{
-        "last_read_id" => %Schema{
+        last_read_id: %Schema{
           type: :string,
           description: "The content of your message."
         }

lib/pleroma/web/pleroma_api/controllers/chat_controller.ex

@@ -120,7 +120,7 @@ def mark_message_as_read(
   end
 
   def mark_as_read(
-        %{body_params: %{"last_read_id" => last_read_id}, assigns: %{user: user}} = conn,
+        %{body_params: %{last_read_id: last_read_id}, assigns: %{user: user}} = conn,
         %{id: id}
       ) do
     with {:ok, chat} <- Chat.get_by_user_and_id(user, id),