n8n: fix build on aarch64

By performing an oraclectomy.

pkgs/applications/networking/n8n/default.nix

@@ -15,6 +15,15 @@ nodePackages.n8n.override {
     pkgs.postgresql
   ];
 
+  # Oracle's official package on npm is binary only (WHY?!) and doesn't provide binaries for aarch64.
+  # This can supposedly be fixed by building a custom copy of the module from source, but that's way
+  # too much complexity for a setup no one would ever actually run.
+  #
+  # NB: If you _are_ actually running n8n on Oracle on aarch64, feel free to submit a patch.
+  preRebuild = lib.optionalString stdenv.isAarch64 ''
+    rm -rf node_modules/oracledb
+  '';
+
   dontNpmInstall = true;
 
   passthru = {