chore(deps): 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] <support@github.com>

.github/workflows/release.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Handle the code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Set up Python 3.10
       uses: actions/setup-python@v4

.github/workflows/testing.yml

@@ -18,7 +18,7 @@ jobs:
 
     steps:
       - name: Handle the code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: "Set up Python 3.10"
         uses: actions/setup-python@v4
@@ -70,7 +70,7 @@ jobs:
             tox-env: pypy3
     steps:
       - name: Handle the code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v4