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] <support@github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -35,7 +35,7 @@ jobs:
           - windows-2025
           - windows-2022
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - run:  bash -x build-cmake.sh
     - run:  bash check.sh
 
@@ -53,7 +53,7 @@ jobs:
           - macos-14
           - macos-13
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - uses: actions/setup-python@v5
       with: {python-version: '3.x'}
     - run:  python -m pip install meson ninja
@@ -74,6 +74,6 @@ jobs:
           - macos-14
           - macos-13
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v5
     - run:  make
     - run:  bash check.sh

.github/workflows/mpi4py.yml

@@ -23,7 +23,7 @@ jobs:
     steps:
 
     - name: Checkout mpi-stubs
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
       with:
         path: mpi-stubs
 
@@ -41,7 +41,7 @@ jobs:
         python-version: 3
 
     - name: Checkout mpi4py
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
       with:
         repository: mpi4py/mpi4py
         path: mpi4py