Fix mypy errors

src/ocrmypdf/_pipeline.py

@@ -900,11 +900,11 @@ def copy_final(
     log.debug('%s -> %s', input_file, output_file)
     with input_file.open('rb') as input_stream:
         if output_file == '-':
-            copyfileobj(input_stream, sys.stdout.buffer)
+            copyfileobj(input_stream, sys.stdout.buffer)  # type: ignore[misc]
             sys.stdout.flush()
         elif hasattr(output_file, 'writable'):
             output_stream = cast(BinaryIO, output_file)
-            copyfileobj(input_stream, output_stream)
+            copyfileobj(input_stream, output_stream)  # type: ignore[misc]
             with suppress(AttributeError):
                 output_stream.flush()
         else:

src/ocrmypdf/pluginspec.py

@@ -28,7 +28,7 @@ if TYPE_CHECKING:
 hookspec = pluggy.HookspecMarker('ocrmypdf')
 
 # pylint: disable=unused-argument
-# mypy:
+# mypy: disable-error-code=empty-body
 
 
 @hookspec(firstresult=True)