Add single-shard keccak integration test

Author: hero78119

.github/workflows/integration.yml

@@ -122,6 +122,11 @@ jobs:
           RUSTFLAGS: "-C opt-level=3"
         run: cargo run --release --package ceno_zkvm --bin e2e -- --platform=ceno --max-cycle-per-shard=1600 examples/target/riscv32im-ceno-zkvm-elf/release/examples/keccak_syscall
 
+      - name: Run multi-shards keccak_syscall single shard-id (release)
+        env:
+          RUSTFLAGS: "-C opt-level=3"
+        run: cargo run --release --package ceno_zkvm --bin e2e -- --platform=ceno --max-cycle-per-shard=1600 --shard-id=1 examples/target/riscv32im-ceno-zkvm-elf/release/examples/keccak_syscall
+
       - name: Run secp256k1_add_syscall (release)
         env:
           RUSTFLAGS: "-C opt-level=3"