[chore] Fix broken SQL Where Wikipedia link

[joaopgrassi]

The Where_SQL Wikipedia page got deleted https://en.wikipedia.org/wiki/Wikipedia:Articles_for_deletion/Where_(SQL) recently and now our link checks are failing.

We have an option to link to the general "SQL Syntax" page, to the operators table, OR use a webarchive link (potentially unstable). For now I went with the first option.

Merge requirement checklist

• CONTRIBUTING.md guidelines followed.
• Change log entry added, according to the guidelines in When to add a changelog entry.
  • If your PR does not need a change log, start the PR title with [chore]
• schema-next.yaml updated with changes to existing conventions.