Update build_and_deploy.yml

Author: fxwiegand

.github/workflows/build_and_deploy.yml

@@ -28,6 +28,8 @@ jobs:
 
       - name: Install stable toolchain
         uses: actions-rs/toolchain@v1
+        with:
+            toolchain: stable
 
       - name: Install alignoth
         run: cargo install alignoth