Bad anchor in releases.md's table of contents

[targos]

On https://github.com/nodejs/node/blob/main/doc/contributing/releases.md

The table content's anchor to "7.1 Updating the release (optional)" is #7-1-updating-the-release-optional

It should be #71-updating-the-release-optional

[bryce-seefieldt]

Would love to tackle this doc fix right away