Bump actions/checkout from 6 to 7

Bumps [actions/checkout](https://github.com/actions/checkout) from 6 to 7.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v6...v7)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '7'
  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

@@ -16,7 +16,7 @@ jobs:
       matrix:
         OS: ["ubuntu-latest", "macos-15", "windows-latest"]
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v7
       with:
         fetch-depth: 0
         submodules: true
@@ -37,7 +37,7 @@ jobs:
       matrix:
         OS: ["ubuntu-latest", "macos-15", "windows-latest"]
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v7
       with:
         fetch-depth: 0
         submodules: true
@@ -52,7 +52,7 @@ jobs:
     if: github.event_name == 'push'
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v7
       with:
         fetch-depth: 0
         submodules: true