Update CI config

Author: taiki-e

.github/workflows/ci.yml

@@ -10,7 +10,7 @@ on:
       - main
       - dev
   schedule:
-    - cron: '0 1 * * *'
+    - cron: '0 0 * * *'
   workflow_dispatch:
 
 env:
@@ -63,7 +63,7 @@ jobs:
         with:
           persist-credentials: false
       - name: Install Rust
-        run: rustup toolchain add nightly --no-self-update && rustup default nightly
+        run: rustup update stable --no-self-update
       - uses: taiki-e/setup-cross-toolchain-action@v1
         with:
           target: ${{ matrix.target }}