Another round of small fixes/improvements for CI and build scripts #621

Job	Run time
bytecode_build (ubuntu-22.04, 4.14.x)	4m 19s
docs	4m 40s
opam_dune_build (ubuntu-22.04, 4.12.x)	5m 2s
opam_dune_build (macos-14, 4.14.x)	6m 48s
build_compat (4.14.x, true, -ubuntu-x86_64)	7m 18s
build (macos-14, 5.2.x)	7m 17s
build_compat (ocaml-variants.4.14.2+options,ocaml-option-musl,ocaml-option-static,ocaml-option-fl...	6m 20s
build (macos-14, 4.14.x, true, -macos-arm64)	5m 5s
build_compat (4.12.x)	6m 59s
build (macos-13, 4.14.x, true, -macos-x86_64)	8m 58s
build_compat (4.08.x)	7m 33s
build (ubuntu-22.04, 5.2.x)	5m 53s
build (ubuntu-22.04, 4.14.x)	2m 25s
build (ubuntu-20.04, 4.14.x)	2m 14s
build (windows-2022, ocaml.4.14.2,system-mingw, true, -windows-x86_64)	14m 3s
build (windows-2019, ocaml.4.14.2,system-mingw,arch-x86_32, true, -windows-i386)	13m 18s
build (windows-2022, ocaml.4.14.2,system-msvc)	10m 56s
build (windows-2019, ocaml.4.14.2,system-msvc,arch-x86_32)	9m 58s
rpc_abicheck	0s
	2h 9m 6s

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