message: Cast string 'base64' to the compatible Encoding type.
diff: @@ -30,6 +30,8 @@ import { createPullRequest } from 'octokit-plugin-create-pull-request';
  import globby from 'globby';
  import { resolveSafeChildPath } from '@backstage/backend-common';
  +export type Encoding = 'utf-8' | 'base64';
  +
  class GithubResponseError extends CustomErrorBase {}
  type CreatePullRequestResponse = {
  @@ -210,8 +212,9 @@ export const createPublishGithubPullRequestAction = ({
  //
  // For example, the original gradle-wrapper.jar is 57.8k in https://github.com/kennethzfeng/pull-request-test/pull/5/files.
  // Its size could be doubled to 98.3K (See https://github.com/kennethzfeng/pull-request-test/pull/4/files)
  + const encoding: Encoding = 'base64';
  return {
  - encoding: 'base64',
  + encoding: encoding,
  content: base64EncodedContent,
  mode: githubTreeItemMode,
  };
  