### Bug description

When both `toc: true` and `number-sections: true` are set, the section number is added twice in the ToC, resulting in dead links when one clicks on them in the ToC.
Small reproducible example (running under quarto `v0.9.566` and RStudio `2022.02.3 Build 492` on macOS Monterey)
```
---
title: "toc-gfm-numbered-sections"
author: "Aymeric Stamm"
format:
  gfm: default
  html: default
editor: visual
toc: true
number-sections: true
---

## H1

### Sub-H1

## H2
```

### Checklist

- [X] [formatted your issue](https://yihui.org/issue/#please-format-your-issue-correctly) so it is easier for us to read?
- [X] included a minimal, self-contained, and reproducible example?
- [X] documented the quarto version you're running, by providing the output produced by `quarto check` in a terminal in your issue?
- [X] documented the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
- [X] documented which operating system you're running? If on Linux, please provide the specific distribution as well.
- [X] upgraded to the latest version, including your versions of R, the RStudio IDE, and relevant R packages?
dragonstyle
2022-06-14T07:39:55Z
astamm
bug crossref
v1.4
open
ToC does not play well when sections are numbered
https://github.com/quarto-dev/quarto-cli/issues/1145