sed bugfix for backslash in sp1 ref

.github/workflows/run-on-runner.yml

@@ -133,7 +133,7 @@ jobs:
         run: |
           for file in ${{ github.workspace }}/benchmarks/*.csv; do
             sed -i '1s/^/instance_type,sp1_ref,/' "$file"
-            sed -i "2,\$s/^/${{ inputs.instance_type }},${{ inputs.sp1_ref }},/" "$file"
+            sed -i "2,\$s|^|${{ inputs.instance_type }},${{ inputs.sp1_ref }},|" "$file"
           done
 
       - name: Upload benchmark results