3.2.0 as submitted to CRAN (#2726)

* Create a second r-devel devcontainer, set it as default

* Need repos set on this image

* DESCRIPTION version

* Copy-edit to NEWS

* empty entry for backports:4.4.0

* Fix up backport_linter for oldrel stuff

* ignore references to removed linter

* to-be-deleted: massive GHA for all versions

* Revert "to-be-deleted: massive GHA for all versions"

This reverts commit b7a34d1.

* Fix up exclusions of large files

re-run roxygenize

Increment version number to 3.1.1

Increment version number to 3.1.0

Don't use rprojroot after all

Just implement a depth restriction, so hopefully we don't recurse into
directories with thousands of files.

Use rprojroot rather than built in functions to find the rproj (if th…

…ere is one)

We were running into catastrophic performance taking 20+ minutes on
CRAN's check machines with the previous code, likely because when
searching for Rprojects a parent directory containing thousands of files
was being searched.

I believe using rprojroot should avoid this.

Update link to point to the github version

As the URL checks are generating a false positive for the local link

Update test version

Run globalVariables in a tryCatch

This avoids an error if the package is not installed on the system

Update links in readme