[R-SIG-Mac] MacOS binaries for R-4.6

[Jeroen Ooms]

As every year, starting this month, the bioconductor development
branch now targets R-4.6 for the planned release in April.

Last year CRAN provided MacOS r-devel package binaries way ahead of
the release, see
https://stat.ethz.ch/pipermail/r-sig-mac/2025-January/015106.html

This was super helpful. It would be great if this can be done again
early in the cycle, especially if there may be upgrades of clang /
libomp planned.