style(lib/dune): apply ocamlformat to silence persistent build red #586

Job	Run time
governance / Security policy checks	4s
governance / Workflow security linter	7s
governance / Code quality + docs	11s
governance / Well-Known (RFC 9116 + RSR)	6s
governance / Language / package anti-pattern policy	13s
governance / Validate Hypatia baseline	5s
governance / Trusted-base reduction policy	5s
governance / Licence consistency	8s
governance / Guix primary / Nix fallback policy	6s
	1m 5s

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