revdep grattan example error after fixing incorrect key

[tdhock]

c806849 is responsible for a new check failure in library(grattan). https://rcdata.nau.edu/genomic-ml/data.table-revdeps/analyze/2025-07-08/grattan.txt

* checking examples ... ERROR
Running examples in 'grattan-Ex.R' failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: differentially_uprate_wage
> ### Title: Differential uprating
> ### Aliases: differentially_uprate_wage
> 
> ### ** Examples
> 
> ws <- c(20e3, 50e3, 100e3)
> from <- "2013-14"
> to <- "2016-17"
> differentially_uprate_wage(ws, from, to)
Error in roll && length(irows) != 1L : invalid 'x' type in 'x && y'
Calls: differentially_uprate_wage ... is.data.table -> [ -> [.data.table -> setattr -> .join_result_key
Execution halted

@MichaelChirico @ben-schwen can you please investigate?

[tdhock]

revdep machine says this is now OK