Fix Rust toolchain action name

Author: louistrue

.github/workflows/docs.yml

@@ -35,7 +35,7 @@ jobs:
           python-version: '3.12'
 
       - name: Setup Rust
-        uses: dtolnay/rust-action@stable
+        uses: dtolnay/rust-toolchain@stable
 
       - name: Cache pip dependencies
         uses: actions/cache@v4