ci: fix risc0 toolchain v2

Author: MarcosNicolau

.github/workflows/build-and-test-rust.yml

@@ -30,12 +30,12 @@ jobs:
           curl -L https://sp1.succinct.xyz | bash
           source /home/runner/.bashrc
            ~/.sp1/bin/sp1up
-           
+
       - name: Install risc0 toolchain
         run: |
          curl -L https://risczero.com/install | bash
          source /home/runner/.bashrc
-         rzup install
+         /home/runner/.risc0/bin/rzup install
 
       - name: Cache Rust dependencies
         uses: actions/cache@v3