wip: try pinning nightly rust?

Author: cpu

.github/workflows/test.yaml

@@ -271,6 +271,8 @@ jobs:
 
       - name: Install nightly rust toolchain
         uses: dtolnay/rust-toolchain@nightly
+        with:
+          toolchain: nightly-2025-03-25
 
       - name: Install cbindgen
         # Pin the installed version of cbindgen so that local usage can be