base: disable garbage collection

Some heavy flake shells with texlive were getting wiped, I can do this
by hand from time to time

base/nix.nix

@@ -18,11 +18,5 @@
       "alarsyo.cachix.org-1:A6BmcaJek5+ZDWWv3fPteHhPm6U8liS9CbDbmegPfmk="
       "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
     ];
-
-    gc = {
-      automatic = true;
-      dates = "03:15";
-      options = "--delete-older-than 30d";
-    };
   };
 }