guix: remove input labels
Summary:
Migrate package definitions to use the new format for propogated inputs. See https://guix.gnu.org/manual/en/html_node/package-Reference.html#index-inputs_002c-of-packages. See also: https://guix.gnu.org/blog/2021/the-big-change/
Backport of core#28965.
Depends on D17245.
Test Plan: Run the guix builds.
Reviewers: #bitcoin_abc, PiRK
Reviewed By: #bitcoin_abc, PiRK
Differential Revision: https://reviews.bitcoinabc.org/D17246