LaTeX tables: column spanner widths are affected by order of the input data

[bzkrouse]

Prework

• Read and agree to the code of conduct and contributing guidelines.
• If there is already a relevant issue, whether open or closed, comment on the existing thread instead of posting a new issue.

Description

First, thank you for all the recent efforts to improve LaTeX capabilities! This issue is somewhat related to #1656.
For tables with a stub and column spanners, the column spanner's width is influenced by the order of the input data.

Reproducible example

[correct behavior] For the table below, the order of the data columns matches the order of the table columns. Widths are correctly set when rendered to latex:

library(gt)
gtcars |> 
  dplyr::select(mfr, model, year, trim) |> 
  dplyr::slice(1:10) |> 
  gt(rowname_col = "mfr") |>
  cols_width(
    mfr ~ pct(55),
    model ~ pct(15),  
    year ~ pct(15),
    trim ~ pct(15)
  ) |>  
  tab_spanner(
    label = "a spanner",
    columns = c(year, trim)
  )

However, if we move mfr (row label) to the last column in the data, the spanner incorrectly inherits the width of the stub column:

gtcars |> 
  dplyr::select(model, year, trim, mfr) |>  
  dplyr::slice(1:10) |> 
  gt(rowname_col = "mfr") |>
  cols_width(
    mfr ~ pct(55),
    model ~ pct(15),  
    year ~ pct(15),
    trim ~ pct(15) 
  ) |>  
  tab_spanner(
    label = "a spanner",
    columns = c(year, trim)
  )

Expected result

I would expect the spanner widths to be independent of the order of the input data. Tables without spanners and/or stubs seem to work fine regardless of the order of the input data.

[olivroy]

Yes, there are a couple of issues with borders + stub in LaTeX, like #1864. @kbrevoort I wonder if you were able to make progress on the issue?