Use risc0 main again now that required changes have been merged

Author: bobbobbio

.github/workflows/ci.yml

@@ -39,7 +39,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           repository: risc0/risc0
-          ref: bobbobbio/rust-1.88
+          ref: main
           path: risc0
 
       - name: set RISC0_HOME