Package 'metacoder' has been archived on CRAN

[willgearty]

metacoder is currently archived on CRAN since October/November: https://cran.r-project.org/package=metacoder. It looks like this is due to a variety of issues with the CRAN checks: https://cran-archive.r-project.org/web/checks/2025/2025-10-18_check_results_metacoder.html.

If metacoder remains archived, we will need to remove it from the Phylogenetics CRAN Task View.
cran-task-views/Phylogenetics#38