core: remove bcache.nix (substituters are taken from nixConfig output of flakes? i suppose?)

Author: mrtnvgr

core/bcache.nix

@@ -5,7 +5,6 @@
     ./packages.nix
     ./fat.nix
     ./overlays.nix
-    ./bcache.nix
     ./home-manager.nix
     ./time-zone.nix
     ./physlock.nix