ci: split clippy/fmt, use .rustfmt.unstable.toml

Author: cpu

.github/workflows/CI.yml

@@ -70,8 +70,8 @@ jobs:
         env:
           RUST_BACKTRACE: 1
 
-  lints:
-    name: Lints
+  clippy:
+    name: Clippy
     runs-on: ubuntu-latest
     steps:
       - name: Checkout sources
@@ -82,15 +82,28 @@ jobs:
       - name: Install stable toolchain
         uses: dtolnay/rust-toolchain@stable
         with:
-          components: rustfmt, clippy
-
-      - name: Run cargo fmt
-        run: cargo fmt --all --check
+          components: clippy
 
       - name: Run cargo clippy
-        if: always()
         run: cargo clippy --locked --all-features
 
+  rustfmt:
+    name: Format
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v6
+        with:
+          persist-credentials: false
+
+      - name: Install nightly toolchain
+        uses: dtolnay/rust-toolchain@nightly
+        with:
+          components: rustfmt
+
+      - name: Check formatting
+        run: cargo +nightly fmt-unstable --check
+
   docs:
     name: Check for documentation errors
     runs-on: ubuntu-latest