ci: generate clean sha256sum hashes with a more selective glob pattern

Author: johnalotoski

.github/workflows/release-upload.yaml

@@ -117,7 +117,7 @@ jobs:
       - name: Checksums
         run: |
           sha256sums_filename="cardano-node-${{ needs.pull.outputs.node_version }}-sha256sums.txt"
-          sha256sum cardano-node-* >> "$sha256sums_filename"
+          sha256sum cardano-node-*-*-* > "$sha256sums_filename"
       - name: Release
         uses: input-output-hk/action-gh-release@v1
         with: