Fence fs.readSyncDyn with fs.readSync

The readSync form whose arguments are checked at run time lowers to
fs.readSyncDyn, which the determinism attestation demotes on. List it as
an alias of fs.readSync so the readSync fence witnesses it.

packages/compiler/src/frontend/lowering/surfaces.ts

@@ -2127,6 +2127,8 @@ export const BUILTIN_MODULE_FN_ALIASES: Record<
     ],
     // The utf8 string overload; the table row is the Buffer-window form.
     writeSync: ["fs.writeStrSync"],
+    // The form whose arguments Node checks at run time.
+    readSync: ["fs.readSyncDyn"],
     // The { recursive, mode } option lowerings.
     mkdirSync: ["fs.mkdirModeSync", "fs.mkdirRecursiveSync", "fs.mkdirRecursiveModeSync"],
     // The { recursive, force } and maxRetries/retryDelay option lowerings.