Fix actions/upload-artifact given a behavior change

See:
https://github.com/actions/download-artifact/blob/main/docs/MIGRATION.md#merging-multiple-artifacts

.github/workflows/test.yml

@@ -15,7 +15,6 @@ jobs:
       matrix:
         smalltalk: [ Pharo64-11, Pharo64-12 ]
         os: [ ubuntu-latest, macos-latest, windows-latest ]
-        ston: [ .ci.ston ]
     runs-on: ${{ matrix.os }}
     name: ${{ matrix.smalltalk }} on ${{ matrix.os }}
     steps:
@@ -27,7 +26,7 @@ jobs:
         with:
           smalltalk-image: ${{ matrix.smalltalk }}
       - name: Load in New Image and Run Tests
-        run: smalltalkci -s ${{ matrix.smalltalk }} ${{ matrix.ston }}
+        run: smalltalkci -s ${{ matrix.smalltalk }} .ci.ston
         shell: bash
         timeout-minutes: 10
         env:
@@ -36,7 +35,7 @@ jobs:
         if: ${{ failure() }}
         uses: actions/upload-artifact@v4
         with:
-          name: Logs
+          name: Logs-${{ matrix.smalltalk }}-${{ matrix.os }}
           path: |
             *.fuel
             PharoDebug.log