Log Message:
pkgtools/pkgchkxx: update to 0.3.1

## 0.3.1 -- 2025-02-10

* Fix an issue where `pkgrrxx` (and possibly `pkgchkxx` also) would die
  when it receives a signal while it's blocking on `waitpid(2)`.
* Fix an issue in 0.3 where ANSI escape sequences would leak into `make`
  output.