bump toolchain in CI

Author: JasonVranek

.github/workflows/ci.yml

@@ -26,7 +26,7 @@ jobs:
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: nightly-2025-06-26
+          toolchain: nightly-2026-01-01
           components: clippy, rustfmt
 
       - name: Install protoc