guix: Remove librt usage from release binaries

Summary:

contrib: remove librt from release deps

guix: backport glibc patch to prevent redundant librt link

This is a backport of core#28069
Depends on D15345

Test Plan:
gitian builds
contrib/guix/guix-build

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D15346