Install testthat 3.0.4 to fix Catch2 error on Ubuntu 22.04

error: size of array ‘altStackMem’ is not an integral constant-expression

https://github.com/r-lib/testthat/blob/main/NEWS.md#testthat-304

Author: jdblischak

data/legacy-package-versions.csv

@@ -41,7 +41,7 @@ R.oo,1.22.0,archive
 stringr,1.3.0,archive
 httr,1.3.1,archive
 sessioninfo,1.0.0,archive
-testthat,2.0.0,archive
+testthat,3.0.4,archive
 promises,1.0.1,archive
 rappdirs,0.3.1,archive
 reticulate,1.15,archive

scripts/download-legacy-versions.R

@@ -62,6 +62,7 @@ deps["knitr", "version"] <- "1.29"
 deps["later", "version"] <- "0.7.4"
 deps["reticulate", "version"] <- "1.15"
 deps["rmarkdown", "version"] <- "1.18"
+deps["testthat", "version"] <- "3.0.4"
 deps["xfun", "version"] <- "0.15"
 deps["yaml", "version"] <- "2.1.19"