flake/packages: test all packages by default

Author: GaetanLepage

Diff for: flake-modules/checks.nix

@@ -27,7 +27,6 @@
         inherit pkgs;
         inherit (pkgs) lib;
       };
-      docs = config.packages.docs ? null;
     };
   };
 }

Diff for: flake-modules/packages.nix

@@ -22,5 +22,8 @@
     in
       docs
       // man-docs;
+
+    # Test that all packages build fine when running `nix flake check`.
+    checks = config.packages;
   };
 }