Reflect musl/glibc correctly in meta.platforms for binary GHCs

[sternenseemann]

We should be able to leverage #195294 (which allows adding proper lib.platforms to the meta.platforms list to my understanding) in order to get rid of the following HACK:

nixpkgs/pkgs/development/compilers/ghc/9.2.4-binary.nix

Lines 423 to 433 in 0c9c29c

	# HACK: since we can't encode the libc / abi in platforms, we need
	# to make the platform list dependent on the evaluation platform
	# in order to avoid eval errors with musl which supports less
	# platforms than the default libcs (i. e. glibc / libSystem).
	# This is done for the benefit of Hydra, so `packagePlatforms`
	# won't return any platforms that would cause an evaluation
	# failure for `pkgsMusl.haskell.compiler.ghc922Binary`, as
	# long as the evaluator runs on a platform that supports
	# `pkgsMusl`.
	platforms = builtins.attrNames ghcBinDists.${distSetName};
	hydraPlatforms = builtins.filter (p: minimal || p != "aarch64-linux") platforms;

cc @amjoseph-nixpkgs