message: [node] Add log for unused config runtime
  Both `runtime: undefined` and `runtime: nodejs` have the same behavior
  but we want to change that in the future.
  The first step is to see if `runtime: nodejs` is currently used at all.
diff: @@ -413,6 +413,11 @@ export const build: BuildV3 = async ({
  )} (must be one of: ${JSON.stringify(ALLOWED_RUNTIMES)})`
  );
  }
  + if (staticConfig.runtime === 'nodejs') {
  + console.log(
  + `Detected unused static config runtime "nodejs" in "${entrypointPath}"`
  + );
  + }
  isEdgeFunction = isEdgeRuntime(staticConfig.runtime);
  }
  