Rectangling data by unnesting list columns

df_unnamed |> unnest_longer(y)

## # A tibble: 6 × 2
##       x     y
##   <dbl> <dbl>
## 1     1    11
## 2     1    12
## 3     1    13
## 4     2    21
## 5     3    31
## 6     3    32