Pin coverage-upload-github-action to SHA

Pin DataDog/coverage-upload-github-action@v1 to commit SHA
d2cf302a39c05e0ad22063360a2bf6ce0cc4906c for supply chain security.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: ManuelPalenzuelaDD

.github/workflows/coverage.yml

@@ -53,7 +53,7 @@ jobs:
       - name: Upload coverage to Datadog
         if: always()
         continue-on-error: true
-        uses: DataDog/coverage-upload-github-action@v1
+        uses: DataDog/coverage-upload-github-action@d2cf302a39c05e0ad22063360a2bf6ce0cc4906c # v1
         with:
           api_key: ${{ secrets.DATADOG_API_KEY }}
           files: lcov.info