[Github][CI] Name premerge artifacts per OS

This patch renames premerge artifacts per OS. Without this, the premerge
artifacts will conflict with each other and the slower running job will
fail to upload the artifact.

.github/workflows/premerge.yaml

@@ -69,7 +69,7 @@ jobs:
       - name: Upload Artifacts
         uses: actions/upload-artifact@65c4c4a1ddee5b72f698fdd19549f0f0fb45cf08 # v4.6.0
         with:
-          name: Premerge Artifacts
+          name: Premerge Artifacts (Linux)
           path: artifacts/
           retention-days: 5
           include-hidden-files: 'true'
@@ -124,7 +124,7 @@ jobs:
       - name: Upload Artifacts
         uses: actions/upload-artifact@65c4c4a1ddee5b72f698fdd19549f0f0fb45cf08 # v4.6.0
         with:
-          name: Premerge Artifacts
+          name: Premerge Artifacts (Windows)
           path: artifacts/
           retention-days: 5
           include-hidden-files: 'true'