Fix T102845: GPU python crash in background mode

`BPYGPU_IS_INIT_OR_ERROR_OBJ` is not implemented in all pygpu functions.

Instead of copying and pasting that call across the API when it has no
gpu context, override the methods with one that always reports error.

source/blender/python/gpu/gpu_py_uniformbuffer.c

@@ -59,8 +59,6 @@ static PyObject *pygpu_uniformbuffer__tp_new(PyTypeObject *UNUSED(self),
                                              PyObject *args,
                                              PyObject *kwds)
 {
-  BPYGPU_IS_INIT_OR_ERROR_OBJ;
-
   GPUUniformBuf *ubo = NULL;
   PyObject *pybuffer_obj;
   char err_out[256] = "unknown error. See console";