title: How to update the PATH in a github action workflow file for a windows-latest hosted runner
body: <p>I'm currently trying to add GitHub actions workflow to a repo...</p>
  
  <p>To do a C++/CMake/swig/python development (i.e. native python library dev), I need to download and install swigwin and have it available in the <code>PATH</code>...</p>
  
  <p>Unfortunately it seems the <code>$env:Path...</code> command is not take into account during the next  subsequent <a href="https://help.github.com/en/actions/reference/workflow-syntax-for-github-actions#jobsjob_idsteps" rel="noreferrer">steps</a></p>
  
  <h1>Example</h1>
  
  <pre><code>name: Python Windows CI
  
  on: [push, pull_request]
  
  jobs:
    # Building using the GitHub runner environment directly.
    build:
      runs-on: windows-latest
      steps:
      - uses: actions/checkout@v2
      - name: Check cmake
        run: cmake --version
      - name: Install swig
        run: |
          (New-Object System.Net.WebClient).DownloadFile("http://prdownloads.sourceforge.net/swig/swigwin-4.0.1.zip","swigwin-4.0.1.zip");
          Expand-Archive .\swigwin-4.0.1.zip .;
          $env:Path += ";.\swigwin-4.0.1";
          swig -version;
      - name: Check swig
        run: swig -version # swig cmdlet not found...
  
  </code></pre>
  
  <h1>Observed</h1>
  
  <pre><code>&gt; Set up job
  &gt; Run actions/checkout@v23s
  &gt; Check cmake
  v Install swig
  ...
  SWIG Version 4.0.1
  ...
  v Check swig
   swig -version
    shell: C:\Program Files\PowerShell\6\pwsh.EXE -command ". '{0}'"
  swig : The term 'swig' is not recognized as the name of a cmdlet, function, script file, or operable program.
  Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
  At D:\a\_temp\0a8dc0e1-ec51-429b-abd0-cb3597e983ac.ps1:2 char:1
  + swig -version
  + ~~~~
  + CategoryInfo          : ObjectNotFound: (swig:String) [], ParentContainsErrorRecordException
  + FullyQualifiedErrorId : CommandNotFoundException
  
  ##[error]Process completed with exit code 1.
  </code></pre>