PY: continue renovation of extension Fixed unchecked malloc for "tail" input data. Fixed inconsistencies in docstrings. Rewritten "growable buffer" to C-code, so it could run without acquiring GIL. Breaking changes: - native object allocation failures now handled at object creation time - some lower level exceptions (e.g. OOM) are not shadowed by brotli.error PiperOrigin-RevId: 810813664