### Bug description

Callouts, such as this note, are given a different amount of leading and trailing whitespace.

<img width="808" alt="image" src="https://github.com/quarto-dev/quarto-cli/assets/362187/21d829ff-0ef7-434b-9d5b-f50c46d4be90">

This is super nit-picky, so feel free to close as a non-issue. We noticed this because the spacing of callouts is different than what we were used to with the admonitions from mkdocs-material: https://squidfunk.github.io/mkdocs-material/reference/admonitions/#usage

<img width="665" alt="image" src="https://github.com/quarto-dev/quarto-cli/assets/362187/be71541b-ea97-438d-80d1-3dada2fc95ed">


### Steps to reproduce

The `_quarto.yml`:

```yaml
project:
  type: website

format:
  html:
    toc: true
    theme: cosmos
```

The `index.qmd`:

````markdown
---
title: callouts
---

This is text before the callout.

::: {.callout-note}
We have one line.
:::

This is text after the callout.
````

### Expected behavior

The leading and trailing whitespace should be consistent, which let a single-line or single-paragraph be vertically centered within the callout.

### Actual behavior

_No response_

### Your environment

_No response_

### Quarto check output

```
[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.1.1: OK
      Dart Sass version 1.55.0: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 1.3.353
      Path: /Applications/RStudio.app/Contents/Resources/app/quarto/bin

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

[✓] Checking Python 3 installation....OK
      Version: 3.9.6
      Path: /Library/Developer/CommandLineTools/usr/bin/python3
      Jupyter: (None)

      Jupyter is not available in this Python installation.
      Install with python3 -m pip install jupyter

[✓] Checking R installation...........OK
      Version: 3.6.3
      Path: /Library/Frameworks/R.framework/Resources
      LibPaths:
        - /Library/Frameworks/R.framework/Versions/3.6/Resources/library
      knitr: 1.42.8
      rmarkdown: 2.20

[✓] Checking Knitr engine render......OK
```
2023-06-02T20:02:40Z
aronatkins
bug
closed
callouts: different amounts of leading/trailing whitespace
https://github.com/quarto-dev/quarto-cli/issues/5798