`number-sections: True` misbehaves slightly when appendix sections are present

Bug description

number-sections: true numbers all sections in the order in which they appear in the source markdown document.

however, this conflicts with the {.appendix} class command which sends the section to the appendix of the document.

Steps to reproduce

Here is a minimal example:

---
format: html
number-sections: true
---

# Section A

# Appendix {.appendix}

# Section B

Expected behavior

I would expect the result to render as

1. Section A
2. Section B
3. Appendix

Actual behavior

Instead the numbers are mangled

1. Section A
3. Section B
2. Appendix

Depending on the underlying code:

• if the fix is too complex, it's probably best to just mention the poor interaction in the docs: the user can fix it by reordering their document
• from the outside, it looks like .appendix should modify the order of the sections in the pandoc AST. If so, maybe it's possible to fix this in a flash by just re-ordering the sections

Your environment

• IDE: vscode
• OS: windows 11

Quarto check output

Quarto 1.5.45
[>] Checking versions of quarto binary dependencies...
Pandoc version 3.2.0: OK
Dart Sass version 1.70.0: OK
Deno version 1.41.0: OK
Typst version 0.11.0: OK
[>] Checking versions of quarto dependencies......OK
[>] Checking Quarto installation......OK
Version: 1.5.45
Path: C:\Users\Guillaume\AppData\Local\Programs\Quarto\bin
CodePage: 1252

[>] Checking tools....................OK
TinyTeX: v2024.06
Chromium: (not installed)

[>] Checking LaTeX....................OK
Using: TinyTex
Path: C:\Users\Guillaume\AppData\Roaming\TinyTeX\bin\windows
Version: 2024

[>] Checking basic markdown render....OK

[>] Checking Python 3 installation....OK
Version: 3.12.4
Path: d:/Desktop/Dojo/quarto_bug_report_listings/.venv/Scripts/python.exe
Jupyter: 5.7.2
Kernels: python3

[>] Checking Jupyter engine render....OK

[>] Checking R installation...........(None)

  Unable to locate an installed version of R.
  Install R from https://cloud.r-project.org/