autoref errors if showkeys is loaded

[u-fischer]

As reported in https://tex.stackexchange.com/q/690741/2388

If amsmath is loaded, it defines \SK@@label to \relax and \HyRef@ShowKeysInit is executed even in final mode:

\documentclass[final]{article}
\usepackage{amsmath}
\usepackage{hyperref}
\usepackage{showkeys}
\begin{document}
\section{The Pythagoras Theorem}\label{sec:pythagoras}
\autoref{sec:pythagoras}
\end{document}

errors with

! Undefined control sequence.
\HyRef@ShowKeysRef ->\SK@