### Bug description

Following the [documentation on sizing mermaid diagram](https://quarto.org/docs/authoring/diagrams.html#sizing), the latest nightly build (1.3.107) running on Ubuntu 20.04 no longer sizes the diagrams differently regardless of the fig-width parameter. I also tried this with the latest stable (1.2.313) and it has the same issue. 

For example, in the following script the diagram under  #Slide 1 is the exact same size as the diagram in #Slide 2. I have tried playing with both and fig-width and fig-height but neither seems to have any effect. 

````md
---
title: Bad Mermaid Sizing
format:
    revealjs
---

# Slide 1

```{mermaid}

%%| fig-width: 5

flowchart LR
  A[Hard edge] --> B(Round edge)
  B --> C{Decision}
```

# Slide 2

```{mermaid}

%%| fig-width: 15

flowchart LR

  A[Hard edge] --> B(Round edge)
  B --> C{Decision}
```
````

Maybe related to some of the fixes for https://github.com/quarto-dev/quarto-cli/issues/2607? 

### Checklist

- [X] Please include a minimal, fully reproducible example in a single .qmd file? Please provide the whole file rather than the snippet you believe is causing the issue.
- [X] Please [format your issue](https://quarto.org/bug-reports.html#formatting-make-githubs-markdown-work-for-us) so it is easier for us to read the bug report.
- [X] Please document the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
- [X] Please document the operating system you're running. If on Linux, please provide the specific distribution.
cscheid
2023-01-14T23:34:06Z
d-chambers
bug mermaid
v1.4
open
Mermaid fig-width no longer works
https://github.com/quarto-dev/quarto-cli/issues/3973