Update CI toolchain to stable

moreal · moreal · commit d60baaeab5a1 · 2022-08-13T18:37:28.000+09:00
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
@@ -263,7 +263,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: dtolnay/rust-toolchain@1.62.1
+      - uses: dtolnay/rust-toolchain@stable
         with:
             components: rustfmt, clippy
       - name: run rustfmt
