ci(github): make Windows test artifacts name unique

If several jobs in the windows-test or vs-test matrices fail, the
upload-artifact action in each job tries to upload the test directories
of the failed tests as "failed-tests-windows.zip", which fails for all
jobs except the one which finishes first with the following error:

    Error: Failed to CreateArtifact: Received non-retryable error:
    Failed request: (409) Conflict: an artifact with this name
    already exists on the workflow run

Make the artifacts name unique by using the 'matrix.nr' token, and
disambiguate the vs-test artifacts from the windows-test ones.

Signed-off-by: Philippe Blain <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: phil-blain

.github/workflows/main.yml

@@ -159,7 +159,7 @@ jobs:
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
       uses: actions/upload-artifact@v4
       with:
-        name: failed-tests-windows
+        name: failed-tests-windows-${{ matrix.nr }}
         path: ${{env.FAILED_TEST_ARTIFACTS}}
   vs-build:
     name: win+VS build
@@ -250,7 +250,7 @@ jobs:
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
       uses: actions/upload-artifact@v4
       with:
-        name: failed-tests-windows
+        name: failed-tests-windows-vs-${{ matrix.nr }}
         path: ${{env.FAILED_TEST_ARTIFACTS}}
   regular:
     name: ${{matrix.vector.jobname}} (${{matrix.vector.pool}})