Temporarily disable chunk

@djnavarro any idea what's going on here? It was failing on GHA with:

```
Error in st_crs.character("+proj=lcc +datum=WGS84") :
19
  invalid crs: +proj=lcc +datum=WGS84
```

maps.Rmd

@@ -190,7 +190,7 @@ In ggplot2, the CRS is controlled by `coord_sf()`, which ensures that every laye
 
 [^first-layer]: If there are multiple data sets with a different associated CRS, it uses the CRS from the first layer.
 
-```{r}
+```{r, eval = FALSE}
 ggplot(oz_votes) +
   geom_sf() + 
   coord_sf(crs = st_crs("+proj=lcc +datum=WGS84"))