docs: fix broken Markdown link (issue #10018)

[pxxad]

Related Issues

• resolves Fix broken Markdown link: https://doi.org/10.1145/3221664.3221674 #10018

Description

Fixes a broken DOI link by replacing it with the correct ACM URL.

Contributing Guidelines

• Read, understood, and followed the contributing guidelines

[stdlib-bot]

Coverage Report

Package	Statements	Branches	Functions	Lines
stats/base/ndarray/variancech	$\color{green}123/123$ $\color{green}+100.00%$	$\color{green}3/3$ $\color{green}+100.00%$	$\color{green}1/1$ $\color{green}+100.00%$	$\color{green}123/123$ $\color{green}+100.00%$

The above coverage report was generated for the changes in this PR.