Fix T97731: Python traceback no longer includes line-numbers

Regression caused by [0] that caused the error message to be
created based on a normalized exception (which hid line numbers).

PyC_ExceptionBuffer{_Simple} & BPy_errors_to_report
no longer clears the exception.

This could have been resolved by changing python_script_error_jump
however that would involve changes to reference counting that are more
risky (noted in code-comment).

[0]: 2d2baeaf04

source/blender/python/intern/bpy_rna.c

@@ -2051,6 +2051,7 @@ static int pyrna_py_to_prop(
                   &itemptr, item, true, "Converting a Python list to an RNA collection") == -1) {
             PyObject *msg = PyC_ExceptionBuffer();
             const char *msg_char = PyUnicode_AsUTF8(msg);
+            PyErr_Clear();
 
             PyErr_Format(PyExc_TypeError,
                          "%.200s %.200s.%.200s error converting a member of a collection "