Why does conf-libclang.15 also require Clang 14 dependencies?

[dc-mak]

Hi, thanks for this convenient opam package. I was wondering/confused as to why the package for version 15 requires parts of Clang 14 dependencies?

opam-repository/packages/conf-libclang/conf-libclang.15/opam

Lines 22 to 24 in 86cb2b7

	["libclang-14-dev" "libclang-cpp14-dev" "llvm-14-dev"]
	{(os-distribution = "debian" & os-version >= "12") |
	(os-distribution = "ubuntu" & os-version = "22.04")}

And this, I'm not used to packaged being an upper bound rather than a lower one, especially for Clang, where (as I understand it) API stability from version to version is not guaranteed?

opam-repository/packages/conf-libclang/conf-libclang.15/opam

Line 50 in 86cb2b7

synopsis: "Virtual package relying on the installation of llvm and clang libraries (<= 15.0.x)"