Windows Artifacts have incorrect Slugification

e.g. https://github.com/pylint-dev/pylint-pytest/actions/runs/6592065982?pr=2

Signed-off-by: Stavros Ntentos <133706+stdedos@users.noreply.github.com>

Author: stdedos

.github/workflows/run-tests.yaml

@@ -42,7 +42,12 @@ jobs:
     steps:
       - uses: actions/checkout@v3
 
-      - name: Slugify GITHUB_REPOSITORY
+      - name: Slugify GITHUB_REPOSITORY (win)
+        if: ${{ matrix.os == 'windows-latest' }}
+        run: echo "GITHUB_REPOSITORY_SLUG=$(echo $env:GITHUB_REPOSITORY -replace '/', '_')" | Out-File -Append -FilePath $env:GITHUB_ENV -Encoding utf8
+
+      - name: Slugify GITHUB_REPOSITORY (non-win)
+        if: ${{ matrix.os != 'windows-latest' }}
         run: echo "GITHUB_REPOSITORY_SLUG=${GITHUB_REPOSITORY////_}" >> $GITHUB_ENV
 
       - name: Set up Python ${{ matrix.python-version }}