devel/R-cran-checkmate: Update to 2.3.4 and add TEST_DEPENDS

Version 2.3.2 failed to build against math/R 4.6.0 because it was
calling Rf_isFrame, a non-API function that was removed in R 4.6.0.
Version 2.3.3 fixed this by dropping usage of isFrame(), and version
2.3.4 removed further deprecated calls to internal R functions.

Release notes: https://github.com/mllg/checkmate/releases/tag/v2.3.3

		https://github.com/mllg/checkmate/releases/tag/v2.3.4

PR: 294423
Approved by: maintainer timeout, implicit build fix
Differential Revision: https://reviews.freebsd.org/D56193