set earlier rust toolchain

Author: darunrs

.github/workflows/ci-lazer-solana-contract.yml

@@ -19,7 +19,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
-          toolchain: stable
+          toolchain: 1.79.0
       - name: install taplo
         run: cargo install --locked [email protected]
       - uses: actions/setup-node@v4