[refactor] Simplify our 0install vendor to remove unused features #28680

Job	Run time
Coverage (5.1.x)	10m 9s
Build (macos-latest, 5.1.x)	13m 16s
Nix (macos-latest)	2m 7s
Build microbenchmarks	2m 41s
Build (ubuntu-latest, 5.1.x)	8m 54s
Nix (ubuntu-latest)	53s
Coq 8.16.1	7m 19s
Build (ocaml-variants.5.3.0+trunk, ubuntu-latest, true)	5m 8s
Build (4.14.x, ubuntu-latest, true)	1m 44s
Create local opam switch (macos-latest, 5)	5m 25s
Documentation	50s
Build (4.14.x, macos-latest, true)	3m 9s
Format	1m 5s
Create local opam switch (macos-latest, 4.14)	5m 55s
Build (5.1.x, macos-13, true)	6m 49s
Create local opam switch (ubuntu-latest, 5)	5m 0s
Build (ocaml-base-compiler.4.14.2,system-msvc, windows-latest)	16m 32s
Build monorepo benchmark docker image	3m 34s
Create local opam switch (ubuntu-latest, 4.14)	5m 8s
Build (ocaml-base-compiler.5.1.1,system-mingw, windows-latest)	10m 40s
Build (4.08.x, ubuntu-latest, true)	1m 44s
Build (4.04.x, ubuntu-latest, true, true)	4m 56s
Build (4.02.x, ubuntu-latest, true)	4m 12s
	2h 7m 10s

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