Fix: Use Rust 1.81.0 for Scrypto build (bulk memory compatibility)

Author: maxgershfield

.github/workflows/build-scrypto.yml

@@ -18,8 +18,8 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Install Rust
-        uses: dtolnay/rust-toolchain@stable
+      - name: Install Rust 1.81 (required for Scrypto)
+        uses: dtolnay/rust-toolchain@1.81.0
         with:
           targets: wasm32-unknown-unknown