ci: upgrade github actions runtimes

Author: claude

.github/workflows/ci.yml

@@ -9,23 +9,22 @@ on:
 env:
   CARGO_TERM_COLOR: always
   RUSTFLAGS: "-D warnings"
-  FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true"
 
 jobs:
   gate:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@stable
         with:
           components: clippy
       - name: Install Node (odw selftest runs under cargo test)
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@v6
         with:
           node-version: 20
       - name: Cache cargo
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry