message: refactor: remove unused pluginBuildDir
diff: "use strict";
  const path = require("path");
  -const PluginBuildDir = require("./classes/PluginBuildDir");
  const addS3BucketToResources = require("./lib/addS3BucketToResources");
  const uploadStaticAssetsToS3 = require("./lib/uploadStaticAssetsToS3");
  const displayStackOutput = require("./lib/displayStackOutput");
  @@ -15,7 +14,6 @@ class ServerlessNextJsPlugin {
  this.provider = this.serverless.getProvider("aws");
  this.providerRequest = this.provider.request.bind(this.provider);
  - this.pluginBuildDir = new PluginBuildDir(this.nextConfigDir);
  this.commands = {};
  