Fix _get_pushes_fd and _get_pulls_fd method signatures

Getters are supposed to have signature "PyObject *(PyObject *self, void *closure)", but the closure argument is often not used.
In wasm it causes a trap if a function is declared with one argument and then called with two.

src/decode.c

@@ -235,7 +235,7 @@ _setfd(ImagingDecoderObject *decoder, PyObject *args) {
 }
 
 static PyObject *
-_get_pulls_fd(ImagingDecoderObject *decoder) {
+_get_pulls_fd(ImagingDecoderObject *decoder, void *closure) {
     return PyBool_FromLong(decoder->pulls_fd);
 }
 

src/encode.c

@@ -299,7 +299,7 @@ _setfd(ImagingEncoderObject *encoder, PyObject *args) {
 }
 
 static PyObject *
-_get_pushes_fd(ImagingEncoderObject *encoder) {
+_get_pushes_fd(ImagingEncoderObject *encoder, void *closure) {
     return PyBool_FromLong(encoder->pushes_fd);
 }