build(nix): updating the cargo nix for 0.15.0

Author: h0lybyte

nix/cargo-pgrx/default.nix

@@ -79,8 +79,8 @@ in
   };
   cargo-pgrx_0_15_0 = mkCargoPgrx {
     version = "0.15.0";
-    hash = "sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA="; # TODO: Replace with actual hash
-    cargoHash = "sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA="; # TODO: Replace with actual hash
+    hash = "sha256-sksRfNV6l8YbdI6fzrEtanpDVV4sh14JXLqYBydHwy0=";
+    cargoHash = "sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA="; # TODO: Replace with actual cargoHash
   };
   inherit mkCargoPgrx;
 }