[ci] Run gha fmt in docker

.github/workflows/fmt-check.yml

@@ -13,28 +13,10 @@ jobs:
       matrix:
         os: ["ubuntu-latest"]
     runs-on: ${{ matrix.os }}
+    container:
+      image: paritytech/ci-linux:production
     steps:
-      - name: Install Rust nightly toolchain
-        uses: actions-rs/toolchain@b2417cde72dcf67f306c0ae8e0828a81bf0b189f # v1.0.7
-        with:
-          profile: minimal
-          toolchain: nightly
-          override: true
-          components: clippy, rustfmt
-
-      - name: Cache Dependencies & Build Outputs
-        uses: actions/cache@88522ab9f39a2ea568f7027eddc7d8d8bc9d59c8 # v3.3.1
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            target
-          key: ${{ runner.os }}-${{ matrix.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
-
       - uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v3.5.2
 
       - name: Cargo fmt
-        uses: actions-rs/cargo@ae10961054e4aa8b4aa7dffede299aaf087aa33b # v1.0.3
-        with:
-          command: fmt
-          args: --all -- --check
+        run: cargo +nightly fmt --all -- --check