meson: Fix cross

The old `CC=.. CXX= .. meson ...` env var hack I removed in
3c00ca03a2 had a side effect of ensuring
that Meson always had access to a native C compiler, which unforunately
it expects in most cases. Thankfully, that will be fixed soon.

pkgs/development/tools/build-managers/meson/default.nix

@@ -3,6 +3,7 @@
 , stdenv
 , writeTextDir
 , substituteAll
+, pkgsHostHost
 }:
 
 python3Packages.buildPythonApplication rec {
@@ -58,6 +59,10 @@ python3Packages.buildPythonApplication rec {
 
   setupHook = ./setup-hook.sh;
 
+  # Ensure there will always be a native C compiler when meson is used, as a
+  # workaround until https://github.com/mesonbuild/meson/pull/6512 lands.
+  depsHostHostPropagated = [ pkgsHostHost.stdenv.cc ];
+
   # 0.45 update enabled tests but they are failing
   doCheck = false;
   # checkInputs = [ ninja pkgconfig ];