⬆️ 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/build.yml

@@ -12,7 +12,7 @@ jobs:
         python-version: ['3.10', '3.11', '3.12', '3.13']
       fail-fast: false
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v7
     - name: Install uv
       uses: astral-sh/setup-uv@v7
     - name: Set up Python ${{ matrix.python-version }}

.github/workflows/git_checks.yml

@@ -18,7 +18,7 @@ jobs:
     name: Find merge conflicts
     steps:
       # Checkout the source code so we have some files to look at.
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v7
       # Run the actual merge conflict finder
     - name: Merge Conflict finder
       uses: olivernybroe/action-conflict-finder@v4.1