title: Bump up version in Github workflow won't change the code
body: <p>I'm using python poetry as package management. For bump up the patch version, I simply run <code>poetry version patch</code>. I moved this function to workflow and it won't change the version string at all!</p>
  <pre><code>name: Bump version
  
  on:   workflow_dispatch:
      inputs:
        version:     
          description: 'Semver type of new version (major / minor / patch)'
          required: true
          type: choice
          options: 
          - patch
          - minor
          - major
  
  jobs:   bump-version:
      runs-on: ubuntu-latest
      steps:
  
      - name: checkout repo
        uses: actions/checkout@v2.4.0
  
      - name: setup python
        uses: actions/setup-python@v2
        with:
          python-version: '3.x'
          architecture: 'x64'
          
      - name: setup poetry
        run: |
          python -m pip install -U pip
          pip install poetry 
    
      - name: Setup Git
        run: |
          git config user.name &quot;${GITHUB_ACTOR}&quot;
          git config user.email &quot;${GITHUB_ACTOR}@teamname.com&quot;
  
      - name: bump version
        run: poetry version ${{ github.event.inputs.version }} #the action is not update the code
  </code></pre>
  <p>I do have the bump up version step as showing above, however, the version string was kept still after pulled and checked, can someone help me?</p>
  <p>Possible reason: Since the workflow needs to checkout (copy the repo) fist, all changes are enter to the copied repo. If so how can I copy back?</p>