fix: disable crane for pg_jsonschema to prevent CI cross-compilation issues

The crane-generated modifiedSrc derivation causes system requirement conflicts
when evaluating for aarch64-darwin on x86_64-linux systems. Disabling crane
for now until cross-compilation support is fully resolved.

Author: yvan-sraka

nix/ext/pg_jsonschema/default.nix

@@ -15,7 +15,7 @@ let
       cargo = rust-bin.stable.${rustVersion}.default;
       mkPgrxExtension = callPackages ../../cargo-pgrx/mkPgrxExtension.nix {
         inherit rustVersion pgrxVersion;
-        useCrane = true;
+        useCrane = false;
       };
       src = fetchFromGitHub {
         owner = "supabase";