guix: remove `util-linux`

hexdump was used for the tests, until CMake. This package is no-longer needed to complete a Guix build (or needed in the CI). util-linux has been in the manifest since Guix was first introduced (3e80ec3e).

Guix build:

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83230468eb9289d294f7bdbb9b410cb7473a2e4dd1463097559dc0752f53cbc0  guix-build-4d668549825c/output/arm-linux-gnueabihf/SHA256SUMS.part
b4d79380642763428b7ca79a66c5920797864b163759081be5369631b4c33c73  guix-build-4d668549825c/output/arm-linux-gnueabihf/bitcoin-4d668549825c-arm-linux-gnueabihf-debug.tar.gz
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17d6297ddd9a94913987c596715e66cff0d91d726d06cca2eeb8f3c94056e8db  guix-build-4d668549825c/output/arm64-apple-darwin/SHA256SUMS.part
02faa61796d88b3cff69feeddc50bc579195da3676e5daace2ffc2332f3cbc1a  guix-build-4d668549825c/output/arm64-apple-darwin/bitcoin-4d668549825c-arm64-apple-darwin-unsigned.tar.gz
0e02ef1418f56f67c472dc785041c1988637e509e77337d2a6eeb69b0c4cd844  guix-build-4d668549825c/output/arm64-apple-darwin/bitcoin-4d668549825c-arm64-apple-darwin-unsigned.zip
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157f1b597eee99ee64722ec28a2770d6fea84bbd711f83ad22ab2bb6b44f15fc  guix-build-4d668549825c/output/powerpc64-linux-gnu/SHA256SUMS.part
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db62e80ca99b163d62fc4d473f87de56d97da52dd37ec5043aaaaf4cf96bde25  guix-build-4d668549825c/output/riscv64-linux-gnu/SHA256SUMS.part
47905dd06466f5c197689f9e02d417f959904762321f6dc70e3bf2cc9a2fc04d  guix-build-4d668549825c/output/riscv64-linux-gnu/bitcoin-4d668549825c-riscv64-linux-gnu-debug.tar.gz
558b9ff6aff7b1a49f7bbba81d57025192aca532e7ee6b90b61a36bba0bfd342  guix-build-4d668549825c/output/riscv64-linux-gnu/bitcoin-4d668549825c-riscv64-linux-gnu.tar.gz
a946b5d730fa12f6e388db31e2e4b5de2c48653f16613146fb848ce9cdee8b81  guix-build-4d668549825c/output/x86_64-apple-darwin/SHA256SUMS.part
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06ef2f4df72377b9f2bb872d624fdcbf391470e4694b85295eb529d90e37ff62  guix-build-4d668549825c/output/x86_64-apple-darwin/bitcoin-4d668549825c-x86_64-apple-darwin-unsigned.zip
bc9fe0032d6f5e9d9576ddb9ea5333bb1d0741731dfa4da4ef1b3daf7dd9241d  guix-build-4d668549825c/output/x86_64-apple-darwin/bitcoin-4d668549825c-x86_64-apple-darwin.tar.gz
4668e50be850961409a4ade5bb7522cc2366e9ab31542247243fa8473d100cb1  guix-build-4d668549825c/output/x86_64-linux-gnu/SHA256SUMS.part
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514a726a2bae3944de8e1dbb606bade4f129f01477d5c607fb5e489b22792462  guix-build-4d668549825c/output/x86_64-linux-gnu/bitcoin-4d668549825c-x86_64-linux-gnu.tar.gz
365a33f3046c680a399d9dabeaca589dd7918642c79f0c33205a724084ff5c1c  guix-build-4d668549825c/output/x86_64-w64-mingw32/SHA256SUMS.part
306c6425c1cebaf9dae65853bc3035d478e7670c333616270d63c4ffd08ec724  guix-build-4d668549825c/output/x86_64-w64-mingw32/bitcoin-4d668549825c-win64-debug.zip
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