Use action/checkout v4 instead of v2 in tests

[mlocati]

No description provided.

[jon-turney]

Oh my! That's wrong! Well spotted!

But I think that should be uses: ./ everywhere, so we use the action from the currently checked out repository.

[mlocati]

But I think that should be uses: ./ everywhere

That's what we currently have: see for example:

    - uses: actions/checkout@v2

    - name: Install Cygwin
      uses: ./
      with:
        platform: ${{ matrix.platform }}
        packages: ${{ matrix.packages }}
        add-to-path: false

so we use the action from the currently checked out repository

We need to checkout the repo: the action doesn't do that automatically.

[mlocati]

PS: about the failing tests see the "Installer freezes in windows-2022 GitHub Action" thread of https://cygwin.com/pipermail/cygwin/2024-October/thread.html

[jon-turney]

Sorry, completely misunderstood this. Somehow my brain decided the v4 tag was the version of this action, not the checkout action. More coffee needed obviously.

So this is just "update the version of the checkout action in tests", and obviously right.

Thanks