chore: bump cpp rust toolchain to 1.81

Signed-off-by: zongz <zongzhe1024@163.com>

Author: zong-zhe

.github/workflows/cpp-test.yaml

@@ -41,7 +41,7 @@ jobs:
     - name: Install Rust
       uses: actions-rs/toolchain@v1
       with:
-        toolchain: 1.80
+        toolchain: 1.81
         override: true
         components: clippy, rustfmt
     - name: Build