bump actions/checkout v4 in README

README.md

@@ -40,20 +40,20 @@ demo: https://github.com/reviewdog/action-depup/pull/4
 ```yaml
 inputs:
  github_token:
- description: 'GITHUB_TOKEN to get latest version with GitHub Release API'
- default: '${{ github.token }}'
+ description: "GITHUB_TOKEN to get latest version with GitHub Release API"
+ default: "${{ github.token }}"
  file:
- description: 'target file'
+ description: "target file"
  required: true
  version_name:
- description: 'target version name. e.g. REVIEWDOG_VERSION'
+ description: "target version name. e.g. REVIEWDOG_VERSION"
  required: true
  repo:
- description: 'target GitHub repository. e.g. reviewdog/reviewdog'
+ description: "target GitHub repository. e.g. reviewdog/reviewdog"
  required: true
  tag:
- description: 'Check tags instead of releases.'
- default: 'false'
+ description: "Check tags instead of releases."
+ default: "false"
  required: false
 ```
 
@@ -65,14 +65,14 @@ inputs:
 name: depup
 on:
  schedule:
- - cron:  '14 14 * * *'
+ - cron: "14 14 * * *"
  workflow_dispatch:
 
 jobs:
  reviewdog:
  runs-on: ubuntu-latest
  steps:
- - uses: actions/checkout@v2
+ - uses: actions/checkout@v4
 
  - uses: reviewdog/action-depup@v1
  id: depup
@@ -102,14 +102,14 @@ If you want to create a PR after, you can use `reviewdog/action-depup/with-pr@v1
 name: depup
 on:
  schedule:
- - cron:  '14 14 * * *'
+ - cron: "14 14 * * *"
  workflow_dispatch:
 
 jobs:
  reviewdog:
  runs-on: ubuntu-latest
  steps:
- - uses: actions/checkout@v2
+ - uses: actions/checkout@v4
  - uses: reviewdog/action-depup/with-pr@v1
  with:
  file: testdata/testfile