## Problem
The tooltip comment we have about removing the `aria-describedby`
attribute to avoid screen readers reading the same text twice is wrong.
## Solution
Make it clear why we do that so that future devs don't remove it.
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## Summary by CodeRabbit
* **Accessibility**
* Clarified accessibility guidance for tooltips and screen-reader labels
across code blocks, database controls, function editors, hooks, and
table actions.
* **Documentation**
* Updated internal comments to more clearly explain why duplicate
tooltip text is avoided for screen readers.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Gildas Garcia
3669fef749