Dialyzer: fix invalid @spec

The callback already defines the @spec and these do not match it.

lib/pleroma/upload/filter/exiftool/strip_location.ex:12:callback_spec_type_mismatch
The @spec return type does not match the expected return type
for filter/1 callback in Pleroma.Upload.Filter behaviour.

Actual:
@spec filter(...) :: {:ok, _}

Expected:
@spec filter(...) :: {:error, _} | {:ok, :filtered | :noop} | {:ok, :filtered, struct()}

lib/pleroma/upload/filter/exiftool/strip_location.ex

@@ -9,8 +9,6 @@ defmodule Pleroma.Upload.Filter.Exiftool.StripLocation do
   """
   @behaviour Pleroma.Upload.Filter
 
-  @spec filter(Pleroma.Upload.t()) :: {:ok, any()} | {:error, String.t()}
-
   # Formats not compatible with exiftool at this time
   def filter(%Pleroma.Upload{content_type: "image/heic"}), do: {:ok, :noop}
   def filter(%Pleroma.Upload{content_type: "image/webp"}), do: {:ok, :noop}

lib/pleroma/upload/filter/mogrifun.ex

@@ -38,7 +38,6 @@ defmodule Pleroma.Upload.Filter.Mogrifun do
     [{"fill", "yellow"}, {"tint", "40"}]
   ]
 
-  @spec filter(Pleroma.Upload.t()) :: {:ok, atom()} | {:error, String.t()}
   def filter(%Pleroma.Upload{tempfile: file, content_type: "image" <> _}) do
     try do
       Filter.Mogrify.do_filter(file, [Enum.random(@filters)])

lib/pleroma/upload/filter/mogrify.ex

@@ -8,7 +8,6 @@ defmodule Pleroma.Upload.Filter.Mogrify do
   @type conversion :: action :: String.t() | {action :: String.t(), opts :: String.t()}
   @type conversions :: conversion() | [conversion()]
 
-  @spec filter(Pleroma.Upload.t()) :: {:ok, :atom} | {:error, String.t()}
   def filter(%Pleroma.Upload{tempfile: file, content_type: "image" <> _}) do
     try do
       do_filter(file, Pleroma.Config.get!([__MODULE__, :args]))