As can be seen in pipuarts [1], this is now a SyntaxWarning with Python 3.12, and will become a SyntaxError in future.
[1] https://piuparts.debian.org/sid/source/m/mistune0.html Setting up python3-mistune0 (0.8.4-4) ... /usr/lib/python3/dist-packages/mistune0.py:435: SyntaxWarning: invalid escape sequence '\|' cells[i][c] = re.sub('\\\\\|', '|', cell)
