pak update from CRAN

[gaborcsardi]

Dear maintainer,

Please see the problems shown on
https://cran.r-project.org/web/checks/check_results_pak.html.

Please correct before 2025-12-22 to safely retain your package on CRAN.

The CRAN Team

checking whether package ‘pak’ can be installed ... WARNING
Found the following significant warnings:
  /home/hornik/tmp/R.check/r-devel-clang/Work/build/include/R_ext/PrtUtil.h:35:2: warning: non-API header file R_ext/PrtUtil.h is obsolete and will be removed [-W#warnings]
See the [install log](https://www.r-project.org/nosvn/R.check/r-devel-linux-x86_64-debian-clang/pak-00install.html) for details.
used C compiler: ‘Debian clang version 21.1.6 (2)’