Confluence - duplicate image caption

Bug description

Figure captions are duplicated when publishing to Confluence.

Steps to reproduce

---
title: "Reproducible Quarto Document"
format: html
engine: jupyter
---

This image attachment leads to duplicate caption. One caption shows underneath the image and another shows as a new paragraph.

![Fake image](test_files/fake_image.png)

Rendering caption as alt-text does not lead to duplicate caption. The caption will only show underneath the image.

![Fake image](test_files/fake_image.png)\

Expected behavior

There should be one caption for the image.

Actual behavior

The caption shows as duplicated.

If I add backslash to end of markdown line to render caption as alt-text, then only the caption directly underneath the image shows.

Your environment

• IDE: VSCode 1.92.2
• macOS Sonoma

Quarto check output

Quarto 1.5.56
[✓] 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: 1.5.56
      Path: /Applications/quarto/bin

[✓] Checking tools....................OK
      TinyTeX: (not installed)
      Chromium: (not installed)

[✓] Checking LaTeX....................OK
      Tex:  (not detected)

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

[✓] Checking Python 3 installation....OK
      Version: 3.11.9
      Path: /Users/soneill/Projects/workflow-research/.venv/bin/python3
      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/

Start by reproducing the issue with the provided Quarto document and test_files/fake_image.png, publishing the result to Confluence. Trace the Confluence publishing entry point and compare the two caption-rendering cases; done means the image has exactly one caption without requiring alt-text syntax.