build(deps): bump actions/checkout from 5 to 7

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 7.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...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

@@ -17,7 +17,7 @@ jobs:
       matrix:
         python: ['3.9', '3.10', '3.11', '3.12', '3.13']
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v7
 
       - name: Setup Python
         uses: actions/setup-python@v5
@@ -36,7 +36,7 @@ jobs:
     name: Static analysis (ruff + mypy)
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v7
       - name: Setup Python
         uses: actions/setup-python@v5
         with:
@@ -79,7 +79,7 @@ jobs:
         ports:
           - 9324:9324
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v7
 
       - name: Setup Python
         uses: actions/setup-python@v5
@@ -115,7 +115,7 @@ jobs:
     name: Conformance suite in sync
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v7
       - name: Verify vendored conformance matches the canonical suite
         run: |
           git clone --depth 1 --branch v1.0.0 https://github.com/BabelQueue/conformance.git "$RUNNER_TEMP/conformance"

.github/workflows/release.yml

@@ -18,7 +18,7 @@ jobs:
       id-token: write   # PyPI Trusted Publishing (OIDC) — no API token needed
       contents: write   # create the GitHub release
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v7
 
       - name: Setup Python
         uses: actions/setup-python@v5