`with_order()` doesn't work with data frame `order_by`

[DavisVaughan]

An edge case, but an easy fix. Replace seq_along() with vec_seq_along() in with_order()

library(dplyr)
#> 
#> Attaching package: 'dplyr'
#> The following objects are masked from 'package:stats':
#> 
#>     filter, lag
#> The following objects are masked from 'package:base':
#> 
#>     intersect, setdiff, setequal, union

df <- tibble(a = c(1, 1, 2), b = c(2, 1, 1))

# Should be `c(2, NA, 1)`
with_order(order_by = df, fun = lag, x = 1:3)
#> [1]  2 NA

^{Created on 2022-07-15 by the reprex package (v2.0.1)}