fix: use github.ref_name instead of github.sha

Author: ARR4N

.github/workflows/libevm-delta.yml

@@ -18,6 +18,6 @@ jobs:
       - name: Diff libevm-base..libevm
         run: |
           .github/workflows/diff_from_libevm-base.sh libevm
-      - name: Diff libevm-base..${{ github.sha }}
+      - name: Diff libevm-base..${{ github.ref_name }}
         run: |
-          .github/workflows/diff_from_libevm-base.sh ${{ github.sha }}
+          .github/workflows/diff_from_libevm-base.sh ${{ github.ref_name }}