Bump actions/checkout from 1 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 1 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v1...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/publish.yml

@@ -10,7 +10,7 @@ jobs:
       id-token: write
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
       - run: python3 -m pip install --upgrade build && python3 -m build

.github/workflows/tox-tests.yml

@@ -24,9 +24,9 @@ jobs:
         python-version: [3.7, 3.8, 3.9, '3.10', 3.11, 3.12, pypy-3.9, pypy-3.10]
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
       if: ${{ ! startsWith(matrix.python-version, 'pypy-') }}
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v4
       if: ${{ startsWith(matrix.python-version, 'pypy-') }}
       # Using actions/checkout@v2 or later with pypy causes an error
       # https://foss.heptapod.net/pypy/pypy/-/issues/3640