Bump actions/checkout from 5 to 6 (#83)

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/pytest-builds.yml

@@ -16,7 +16,7 @@ jobs:
         arch: ['x64', 'x86']
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         submodules: true
 
@@ -53,7 +53,7 @@ jobs:
         python-version: ['3.10', '3.11', '3.12', '3.13']
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         submodules: true
 
@@ -89,7 +89,7 @@ jobs:
         python-version: ['3.10', '3.11', '3.12', '3.13']
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         submodules: true
 

.github/workflows/release-wheels.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         submodules: true
 
@@ -132,7 +132,7 @@ jobs:
             platform_id: macosx_x86_64
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         submodules: true
 
@@ -195,7 +195,7 @@ jobs:
           platform_id: macosx_arm64
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         submodules: true