message: [next] share cache between `nft` runs
  This should result in faster Lambda tracing, as it avoids duplicate work.
diff: @@ -1089,19 +1089,25 @@ export async function build({
  console.time(tracingLabel);
  }
  + const nftCache = Object.create(null);
  +
  const {
  fileList: apiFileList,
  reasons: apiReasons,
  } = await nodeFileTrace(apiPages, {
  base: baseDir,
  processCwd: entryPath,
  + cache: nftCache,
  });
  + debug(`node-file-trace result for api routes: ${apiFileList}`);
  +
  const { fileList, reasons: nonApiReasons } = await nodeFileTrace(
  nonApiPages,
  {
  base: baseDir,
  processCwd: entryPath,
  + cache: nftCache,
  }
  );
  