Upgrade docusaurus from 2 to 3. (#1768) #6656

Job	Run time
Build haddock using nix	1m 8s
Build & test (hydra-plutus)	1m 17s
nix flake check	4m 15s
Build & test (hydra-tui)	3m 4s
Build & test (hydra-node)	8m 18s
Build & test (hydra-tx)	1m 44s
Build & test (hydra-cluster)	10m 12s
Benchmarks (hydra-node, tx-cost, --output-directory $(pwd)/../benchmarks)	2m 15s
Benchmarks (hydra-node, micro, -o $(pwd)/../benchmarks/ledger-bench.html)	1m 36s
Build specification using nix	1m 25s
Benchmarks (hydra-cluster, bench-e2e, datasets datasets/1-node.json datasets/3-nodes.json --outpu...	4m 0s
Compute cost differences	0s
Publish benchmark results	0s
Documentation	3m 13s
Publish test results	10s
	42m 37s

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