Remove unused functions #6487

Job	Run time
Build haddock using nix	3m 31s
Build & test (hydra-plutus)	1m 21s
Build & test (hydra-tui)	3m 48s
Benchmarks (hydra-node, tx-cost, --output-directory $(pwd)/../benchmarks)	2m 33s
Build specification using nix	1m 34s
Build & test (hydra-node)	6m 21s
nix flake check	7m 23s
Benchmarks (hydra-node, micro, -o $(pwd)/../benchmarks/ledger-bench.html)	1m 41s
Build & test (hydra-tx)	1m 45s
Benchmarks (hydra-cluster, bench-e2e, datasets datasets/1-node.json datasets/3-nodes.json --outpu...	5m 35s
Build & test (hydra-cluster)	7m 19s
Compute cost differences	3m 59s
Publish benchmark results	5s
Documentation	1s
Publish test results	1s
	46m 57s

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