It seems the `self-contained` doesn’t work for single HTML generation in the latest update.

To reproduce:
```
---
title: "ggplot2 demo"
author: "Norah Jones"
date: "5/22/2021"
format:
  html:
    fig-width: 8
    fig-height: 4
    code-fold: true
    self-contained: true
---


## Air Quality

@fig-airquality further explores the impact of temperature on ozone level.

```{r}
#| label: fig-airquality
#| fig-cap: Temperature and ozone level.
#| warning: false

library(ggplot2)

ggplot(airquality, aes(Temp, Ozone)) +
  geom_point() +
  geom_smooth(method = "loess"
)
```
```

dragonstyle
2022-05-29T16:19:36Z
jlduan
closed
`self-contained` doesn’t work
https://github.com/quarto-dev/quarto-cli/issues/1016