knightos: reduce build time dependency graph

Using asciidoc-full was unnecessary to build KnightOS-related packages
since only the a2x command matters. This change makes
cross-compilation far more noticeably faster. Closure size for each
package reduced from around 7 MB to 2 MB.

pkgs/development/tools/knightos/kcc/default.nix

@@ -12,7 +12,9 @@ stdenv.mkDerivation rec {
     sha256 = "13sbpv8ynq8sjackv93jqxymk0bsy76c5fc0v29wz97v53q3izjp";
   };
 
-  nativeBuildInputs = [ cmake bison flex ];
+  strictDeps = true;
+
+  nativeBuildInputs = [ bison cmake flex ];
 
   buildInputs = [ boost ];