Table with "auto" colwidths is hidden when calling openXL or saveWorkbook twice

[jey1401]

Describe the bug
After setting column widths to "auto", table columns are hidden in Excel on second call to openXL (or saveWorkbook).
Warnings appear on second call.

To Reproduce

library(openxlsx)

wb = createWorkbook()
addWorksheet(wb, "test")
writeDataTable(wb, sheet = "test", iris)

setColWidths(wb, sheet = "test", cols = 1:5, widths = "auto")

openXL(wb) # ok
openXL(wb) # bug: table is hidden in Excel
#> Warning in .self$setColWidths(i): NAs introduced by coercion
#> Warning in .self$setColWidths(i): NAs introduced by coercion

#> Warning in .self$setColWidths(i): NAs introduced by coercion

#> Warning in .self$setColWidths(i): NAs introduced by coercion

#> Warning in .self$setColWidths(i): NAs introduced by coercion

^{Created on 2023-08-09 by the reprex package (v2.0.1)}

Expected behavior
Table columns should be shown.
File should not change on successive calls to openXL or saveWorkbook.