Bump actions/checkout from 4 to 5

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 to 5.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v4...v5)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '5'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/build-release.yml

@@ -16,7 +16,7 @@ jobs:
           - { name: "3.9-ipython8", python: "3.9", tox: py39-ipython8 }
           - { name: "3.13-ipython8", python: "3.13", tox: py13-ipython8 }
     steps:
-      - uses: actions/checkout@v4.0.0
+      - uses: actions/checkout@v5
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ matrix.python }}
@@ -27,7 +27,7 @@ jobs:
     name: Build package
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: actions/setup-python@v5
         with:
           python-version: "3.13"
@@ -50,7 +50,7 @@ jobs:
     if: startsWith(github.ref, 'refs/tags')
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4.0.0
+      - uses: actions/checkout@v5
       - uses: actions/setup-python@v5
         with:
           python-version: "3.13"