tables are opaque white instead of transparent with some column layouts

Bug description

I first discovered this with bslib::value_box() but it seems more generalizable to divs with background colors that have HTML tables in them (this doesn't seem to impact markdown tables). With the default .column-body the cells of the table are translucent, but with other layouts the table has an opaque white background. Without html-table-processing: none all the tables appear white and grey striped.

Steps to reproduce

---
format:
  html:
    html-table-processing: none
---

```{r}
tb <- shiny::markdown(knitr::kable(data.frame(x = c("A", "B", "C"), y = 1:3, z = rnorm(3)), format = "pipe"))
```


::: {.column-body style="background-color: blue;"}
```{r}
#| echo: false
#| layout-ncol: 5
tb;tb;tb;tb;tb
```
:::

::: {.column-body-outset-left style="background-color: blue;"}
```{r}
#| echo: false
#| layout-ncol: 5
tb;tb;tb;tb;tb
```
:::

::: {.column-body-outset-right style="background-color: blue;"}
```{r}
#| echo: false
#| layout-ncol: 5
tb;tb;tb;tb;tb
```
:::

## What about regular markdown tables?

::: {.column-body style="background-color: blue;"}
|x  |  y|          z|
|:--|--:|----------:|
|A  |  1| -0.7668372|
|B  |  2| -1.2611264|
|C  |  3| -1.2509172|
:::

::: {.column-body-outset-left style="background-color: blue;"}
|x  |  y|          z|
|:--|--:|----------:|
|A  |  1| -0.7668372|
|B  |  2| -1.2611264|
|C  |  3| -1.2509172|
:::

::: {.column-body-outset-right style="background-color: blue;"}
|x  |  y|          z|
|:--|--:|----------:|
|A  |  1| -0.7668372|
|B  |  2| -1.2611264|
|C  |  3| -1.2509172|
:::

Expected behavior

I would expect the color of the tables to be consistent. I'd assume that maybe html-table-processing: none should produce tables with no background color (transparent).

Actual behavior

Different behavior depending on column layout

Your environment

• IDE: Rstudio 2023.12.0+369
• OS: macOS 14.2.1

Quarto check output

Quarto 1.4.506
[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.1.9: OK
      Dart Sass version 1.69.5: OK
      Deno version 1.37.2: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 1.4.506
      Path: /Applications/quarto/bin

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

[✓] Checking LaTeX....................OK
      Using: TinyTex
      Path: /Users/ericscott/Library/TinyTeX/bin/universal-darwin
      Version: 2023

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

[✓] Checking Python 3 installation....OK
      Version: 3.10.9 (Conda)
      Path: /usr/local/Caskroom/miniconda/base/bin/python
      Jupyter: 5.3.0
      Kernels: python3

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

[✓] Checking R installation...........OK
      Version: 4.3.1
      Path: /Library/Frameworks/R.framework/Versions/4.3-x86_64/Resources
      LibPaths:
        - /Users/ericscott/Library/R/x86_64/4.3/library
        - /Library/Frameworks/R.framework/Versions/4.3-x86_64/Resources/library
      knitr: 1.45
      rmarkdown: 2.25

[✓] Checking Knitr engine render......OK

Use the supplied .qmd reproduction as the entry point and render it with html-table-processing: none. Inspect the generated HTML and CSS for the column-body, column-body-outset-left, and column-body-outset-right layouts; done means table backgrounds are transparent and consistent across those layouts.