ci: add Miri test job and skip slow tests under Miri

Add a Miri job to CI with --all-features to catch undefined behavior.
Skip test_node_from_files3 and test_arbitrary_precision under Miri
as they are too slow for the interpreter.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: liuq19

.github/workflows/ci.yml

@@ -75,6 +75,20 @@ jobs:
         - uses: dtolnay/rust-toolchain@nightly
         - run: ./scripts/test.sh
 
+  miri:
+    name: Miri
+    runs-on: ubuntu-latest
+    timeout-minutes: 45
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: true
+      - uses: dtolnay/rust-toolchain@nightly
+        with:
+          components: miri
+      - name: Run Miri
+        run: cargo miri test --all-features
+
   clippy_lint:
     name: Format check
     runs-on: ubuntu-latest

src/value/node.rs

@@ -1904,6 +1904,7 @@ mod test {
 
     #[test]
     #[cfg(not(target_arch = "wasm32"))]
+    #[cfg(not(miri))]
     fn test_node_from_files3() {
         use std::fs::DirEntry;
         let path = env!("CARGO_MANIFEST_DIR").to_string() + "/benchmarks/benches/testdata/";
@@ -2101,6 +2102,7 @@ mod test {
     }
 
     #[test]
+    #[cfg(not(miri))]
     fn test_arbitrary_precision() {
         use crate::Deserializer;