chore(deps): bump actions/checkout from 3 to 4

.github/workflows/codestyle.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - name: checkout
-        uses: actions/checkout@v3.3.0
+        uses: actions/checkout@v4
       - name: ormolu
         uses: mrkkrp/ormolu-action@v14
         with:
@@ -37,7 +37,7 @@ jobs:
           cabal install --allow-newer=base "cabal-fmt-0.1.6"
 
       - name: checkout
-        uses: actions/checkout@v3.3.0
+        uses: actions/checkout@v4
 
       - name: Check formatting of Cabal project description
         run: |

.github/workflows/haddock-coverage.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - name: checkout
-        uses: actions/checkout@v3.3.0
+        uses: actions/checkout@v4
       - name: Cache Cabal files
         uses: actions/cache@v3.2.6
         with:

.github/workflows/haskell-ci.yml

@@ -138,7 +138,7 @@ jobs:
           key: ${{ runner.os }}-${{ matrix.compiler }}-tools-3134785e
           path: ~/.haskell-ci-tools
       - name: checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           path: source
       - name: initial cabal.project for sdist