Vulnerability to retiring spatial infrastructure packages

[rsbivand]

Email from April: I see that maptools is still in Depends: in 2.2-9, but I can't see any use in code. I guess that it may be used in examples - if so, move it to Suggests: and use if conditions to protect examples from running if it is not found, in the usual way: https://cran.r-project.org/doc/manuals/r-release/R-exts.html#Suggested-packages, and using print() to print objects to be shown inside the if condition.

Now, see https://r-spatial.org/r/2023/05/15/evolution4.html and https://r-spatial.github.io/evolution/; maptools will be archived in October 2023. I tried discarding maptools in DESCRIPTION and NAMESPACE, adding sf to Suggests: in DESCRIPTION, and then get from CMD check:
00check.log
Replace maptools::write*Shape (which has been deprecated for many years) by as(st_read(), "Spatial") as per https://r-spatial.org/r/2023/05/15/evolution4.html.

[rsbivand]

Thanks!