Python: Add more useful information when attempting to pass incorrect attributes to GPUVertBuf.attr_fill

This simply adds the name of the incorrect parameter to the error message.

Differential Revision: https://developer.blender.org/D14103

Reviewed by Jeroen Bakker

source/blender/python/gpu/gpu_py_vertex_buffer.c

@@ -292,7 +292,7 @@ static PyObject *pygpu_vertbuf_attr_fill(BPyGPUVertBuf *self, PyObject *args, Py
     const char *name = PyUnicode_AsUTF8(identifier);
     id = GPU_vertformat_attr_id_get(format, name);
     if (id == -1) {
-      PyErr_SetString(PyExc_ValueError, "Unknown attribute name");
+      PyErr_Format(PyExc_ValueError, "Unknown attribute '%s'", name);
       return NULL;
     }
   }