fix(p2-shim): ns mangnitude used in fs while building datetimes

Author: vados-cosmonic

packages/preview2-shim/lib/nodejs/filesystem.js

@@ -39,7 +39,7 @@ const symbolDispose = Symbol.dispose || Symbol.for("dispose");
 const isWindows = platform === "win32";
 const isMac = platform === "darwin";
 
-const nsMagnitude = 1_000_000_000_000n;
+const nsMagnitude = 1_000_000_000n;
 function nsToDateTime(ns) {
   const seconds = ns / nsMagnitude;
   const nanoseconds = Number(ns % nsMagnitude);