`cols_width()` not working when using `cols_merge()` for PDF output

[snhansen]

Description

Widths set with cols_width() isn't respected when using cols_merge() and when the output is PDF.

Reproducible example

Consider this Quarto document:

---
format: pdf
---

```{r}
#| echo: false
library(gt)
sp500 |>
  dplyr::slice(50:55) |>
  dplyr::select(-volume, -adj_close) |>
  gt() |>
  cols_align(
	columns = everything(),
	align = "right"
  ) |>
  cols_merge(
	columns = c(open, close),
	pattern = "{1}-{2}"
  ) |>
  cols_merge(
	columns = c(low, high),
	pattern = "{1}-{2}"
  ) |>
  cols_width(
	date ~ px(100),
	c("open", "low") ~ px(200)
  )
```

Expected result

The table created doesn't respect the widths set:

When output as html, everything looks fine:

Session info

> sessionInfo()
R version 4.4.0 (2024-04-24 ucrt)
Platform: x86_64-w64-mingw32/x64
Running under: Windows 10 x64 (build 19045)

Matrix products: default


locale:
[1] LC_COLLATE=Danish_Denmark.utf8     LC_CTYPE=Danish_Denmark.utf8       LC_MONETARY=Danish_Denmark.utf8    LC_NUMERIC=C                      
[5] LC_TIME=English_United States.1252

time zone: Europe/Copenhagen
tzcode source: internal

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] marginaleffects_0.20.1 patchwork_1.2.0        glue_1.7.0             parameters_0.21.7      ggpomological_0.1.2    epoxy_1.0.0           
 [7] gt_0.11.0              lubridate_1.9.3        forcats_1.0.0          stringr_1.5.1          dplyr_1.1.4            purrr_1.0.2           
[13] readr_2.1.5            tidyr_1.3.1            tibble_3.2.1           ggplot2_3.5.1          tidyverse_2.0.0       

loaded via a namespace (and not attached):
 [1] sass_0.4.9         utf8_1.2.4         generics_0.1.3     xml2_1.3.6         lattice_0.22-6     stringi_1.8.4      hms_1.1.3          digest_0.6.35     
 [9] magrittr_2.0.3     evaluate_0.23      grid_4.4.0         timechange_0.3.0   estimability_1.5.1 mvtnorm_1.2-5      fastmap_1.2.0      processx_3.8.4    
[17] ps_1.7.6           fansi_1.0.6        scales_1.3.0       cli_3.6.2          rlang_1.1.4        reprex_2.1.0       munsell_0.5.1      commonmark_1.9.1  
[25] yaml_2.3.8         withr_3.0.0        tools_4.4.0        datawizard_0.11.0  tzdb_0.4.0         coda_0.19-4.1      colorspace_2.1-0   bayestestR_0.13.2 
[33] vctrs_0.6.5        R6_2.5.1           lifecycle_1.0.4    emmeans_1.10.2     fs_1.6.4           insight_0.20.0     callr_3.7.6        clipr_0.8.0       
[41] pkgconfig_2.0.3    pillar_1.9.0       gtable_0.3.5       Rcpp_1.0.12        data.table_1.15.4  xfun_0.44          tidyselect_1.2.1   knitr_1.47        
[49] rstudioapi_0.16.0  xtable_1.8-4       htmltools_0.5.8.1  rmarkdown_2.27     compiler_4.4.0     markdown_1.13