Correct version guard for dune formatting change #30043

Job	Run time
Build (macos-latest, 5.1.x)	14m 12s
Build (ubuntu-latest, 5.1.x)	9m 2s
Format	1m 7s
Documentation	3m 22s
Nix (macos-latest)	2m 44s
Nix (ubuntu-latest)	55s
Build (ocaml-variants.5.4.0+trunk, ubuntu-latest, true)	1m 22s
Build (4.14.x, ubuntu-latest, true)	1m 17s
Build (4.14.x, macos-latest, true)	2m 13s
Coq 8.16.1	7m 13s
Build (5.1.x, macos-13, true)	3m 40s
Build microbenchmarks	2m 34s
Build (ocaml-base-compiler.4.14.2,system-msvc, windows-latest)	8m 0s
Build (ocaml-base-compiler.5.1.1,system-mingw, windows-latest)	7m 48s
Create local opam switch (macos-latest, 5)	6m 12s
Build monorepo benchmark docker image	3m 48s
Build (4.08.x, ubuntu-latest, true)	1m 26s
Create local opam switch (macos-latest, 4.14)	6m 11s
Wasm_of_ocaml	10m 39s
Create local opam switch (ubuntu-latest, 5)	5m 27s
Create local opam switch (ubuntu-latest, 4.14)	4m 53s
	1h 44m 5s

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