[CI] make fmt job like fellows/runtimes

.github/workflows/ci.yml

@@ -72,23 +72,6 @@ jobs:
           name: encointer-collator-${{ github.sha }}
           path: target/release/encointer-collator
 
-  fmt:
-    name: cargo fmt
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        rust: [ nightly ]
-        rust-target: [ x86_64-unknown-linux-gnu ]
-    env:
-      RUST_BACKTRACE: full
-      RUSTV: ${{ matrix.rust }}
-      TARGET: ${{ matrix.rust-target }}
-    steps:
-      - uses: actions/checkout@v3
-
-      - name: Fmt
-        run: cargo +nightly fmt --all
-
   cargo-toml-fmt:
     runs-on: ubuntu-latest
     container: "tamasfe/taplo:0.7.0-alpine"
@@ -151,7 +134,7 @@ jobs:
     name: Draft Release
     if: startsWith(github.ref, 'refs/tags/')
     runs-on: ubuntu-latest
-    needs: [ create_artifacts, build_primary_binaries, fmt ]
+    needs: [ create_artifacts, build_primary_binaries ]
     outputs:
       release_url: ${{ steps.create-release.outputs.html_url }}
       asset_upload_url: ${{ steps.create-release.outputs.upload_url }}

.github/workflows/fmt.yml

@@ -0,0 +1,34 @@
+name: "Rustfmt (check)"
+
+on:
+  push:
+    branches:
+      - master
+    tags:
+      - '[0-9]+.[0-9]+.[0-9]+'
+      - '[0-9]+.[0-9]+.[0-9]+-dev*'
+  pull_request:
+    branches: [ master ]
+  workflow_dispatch:
+    inputs:
+      verbose:
+        description: "Set --verbose to get verbose build output"
+        required: false
+        default: 'true'
+
+jobs:
+  rustfmt:
+    runs-on: ubuntu-22.04
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Set rust version via common env file
+        run: cat .github/env >> $GITHUB_ENV
+
+      - name: Install nightly toolchain
+        run: rustup toolchain install "nightly-$RUST_NIGHTLY_VERSION" --profile minimal --component rustfmt
+
+      - name: Rustfmt (check)
+        run: cargo +nightly-$RUST_NIGHTLY_VERSION fmt --all -- --check