Fixed wrong hypen location in GitHub validate PR action

[qstokkink]

Related to #1056

New error:

      - uses: actions/setup-python@v4
      - with:
          python-version: ${{ matrix.version }}
        run: python --version
>>
Invalid workflow file: .github/workflows/pr-comment-validate.yml#L18
The workflow is not valid. .github/workflows/pr-comment-validate.yml (Line: 18, Col: 9): Unexpected value 'run' .github/workflows/pr-comment-validate.yml (Line: 16, Col: 9): Required property is missing: uses

Previous error:

      - uses: actions/setup-python@v4
        with:
          python-version: ${{ matrix.version }}
        run: python --version
>>
Error: .github#L1
a step cannot have both the `uses` and `run` keys

This PR:

• Fixed previous PR making the with of the uses a new step instead of the run (oops).

Documentation referenced: https://docs.github.com/en/actions/using-jobs/using-a-matrix-for-your-jobs#example-expanding-configurations

Note that this is PR 3/?, without any guarantees on the upper limit needed to get this running.

[qstokkink]

validate