Bug: `table_shell()` does not hide column counts

[wwojciech]

The (N=...) values remain visible in the rendered shell even though the shell should suppress them:

tbl <- basic_table(show_colcounts = TRUE) |>
  split_cols_by("ARM") |>
  analyze("AGE") |>
  build_table(DM)
tbl
       A: Drug X   B: Placebo   C: Combination
        (N=121)     (N=106)        (N=129)    
——————————————————————————————————————————————
Mean     34.91       33.02          34.57

table_shell(tbl)
       A: Drug X   B: Placebo   C: Combination
        (N=121)     (N=106)        (N=129)    
——————————————————————————————————————————————
Mean     xx.xx       xx.xx          xx.xx