BUG: investigate issue in ExecutableBooks/sphinx-exercise (LaTeX)

[mmcky]

Hi @mmcky,

This appears to be an interesting bug!

When meta tags are used in the solution, as in the example below:

```{code-cell} ipython3
---
mystnb:
  figure:
    caption: Asymptotic bias of Cagan's estimator for different $\lambda$
    name: fig-cagan-bias-lambda
---

The PDF builder produces the following error:

! LaTeX Error: Not in outer par mode.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...                                              
                                                  
l.47746 \begin{figure}[htbp]
                            
? 
! Emergency stop.
 ...                                              
                                                  
l.47746 \begin{figure}[htbp]

Removing the tags resolves the issue.

Originally posted by @HumphreyYang in QuantEcon/lecture-python-advanced.myst#319 (comment)

[mmcky]

@HumphreyYang is this specifically in solution and exercise directives?

[HumphreyYang]

Many thanks @mmcky!

I only found this in the solution directory because that's where figures typically are. I can test it in exercise directives as well.