De-register a package

From: Graham Perrin <grahamperrin_at_gmail.com>
Date: Sat, 28 Aug 2021 12:26:44 UTC
I can't recall how this one package crept in from FreeBSD-base (let's 
assume PEBKAM), but I'd like to be without it. To not have spurious 
output in response to `pkg check -Bsd`, and so on.

How to de-register?

% pkg info FreeBSD-clibs
FreeBSD-clibs-14.snap20210513182414
Name           : FreeBSD-clibs
Version        : 14.snap20210513182414
Installed on   : Sat May 15 20:29:08 2021 BST
Origin         : base
Architecture   : FreeBSD:14:amd64
Prefix         : /
Categories     : base
Licenses       : BSD2CLAUSE
Maintainer     : re@FreeBSD.org
WWW            : https://www.FreeBSD.org
Comment        : Core C Libraries
Shared Libs provided:
         libdl.so.1
         libssp.so.0
         libedit.so.8
         librt.so.1
         libgcc_s.so.1
         libncursesw.so.9
         libm.so.5
         libc.so.7
         libthr.so.3
         libcxxrt.so.1
         libc++.so.1
Annotations    :
         FreeBSD_version: 1400013
         repo_type      : binary
         repository     : FreeBSD-base
Flat size      : 5.79MiB
Description    :
Core C Libraries
% pkg info -x ^FreeBSD-
FreeBSD-clibs-14.snap20210513182414
freebsd-release-manifests-20210413
%