build(deps): bump actions/checkout from 3 to 4 (except haskell-ci workflow)

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v3...v4)

.github/workflows/hlint.yaml

@@ -8,7 +8,7 @@ jobs:
   hlint:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     - name: 'Set up HLint'
       uses: haskell/actions/hlint-setup@v2

.github/workflows/nix.yml

@@ -20,7 +20,7 @@ jobs:
             experimental-features = nix-command flakes
             access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
       - name: Clone project
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Build
         # "nix build" builds with full optimization and includes a profiling
         # build, so just the build of xmonad-contrib itself takes 3 minutes.

.github/workflows/packdeps.yml

@@ -13,7 +13,7 @@ jobs:
 
     steps:
       - name: Clone project
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Setup Haskell
         uses: haskell/actions/setup@v2
         with:

.github/workflows/stack.yml

@@ -31,7 +31,7 @@ jobs:
 
     steps:
       - name: Clone project
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Install C dependencies
         run: |