Bump actions/checkout from 3 to 4

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](actions/checkout@v3...v4)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/test_matrix.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ${{ matrix.platform }}
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
         submodules: true
 

.github/workflows/tests.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Set up Python
       uses: actions/setup-python@v4
       with:

.github/workflows/valgrind.yml

@@ -32,7 +32,7 @@ jobs:
 
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         with:
           submodules: false
 

.github/workflows/wheels.yml

@@ -15,7 +15,7 @@ jobs:
     name: Make SDist
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
 
     - name: Build SDist
       run: pipx run build --sdist
@@ -34,7 +34,7 @@ jobs:
         os: [ubuntu-latest, windows-latest, macos-latest]
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       with:
         submodules: true