ci: Fix ARM builds

Author: nonperforming

.github/workflows/launcher.yml

@@ -35,8 +35,10 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4.2.2
-      - name: Setup Rust
-        run: rustup update ${{ matrix.toolchain }} && rustup default ${{ matrix.toolchain }}
+      - name: Setup rust
+        uses: dtolnay/rust-toolchain@b3b07ba8b418998c39fb20f53e8b695cdcc8de1b
+        with:
+          toolchain: ${{ matrix.toolchain }}
       - name: Build
         run: cargo build --verbose
       - name: Upload artifact