Bump actions/checkout from 6 to 7 (#881)

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

Author: dependabot[bot]

.github/workflows/checks.yaml

@@ -23,7 +23,7 @@ jobs:
     timeout-minutes: 15
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       # Container runs as different user than repo owner, causing "dubious ownership" errors.
       # Tests that run subprocesses (e.g. test_distributed.py) need git commands to work.
@@ -80,7 +80,7 @@ jobs:
         working-directory: param_decomp_lab/app/frontend
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       - name: Install dependencies
         run: npm install

.github/workflows/claude.yaml

@@ -25,7 +25,7 @@ jobs:
       id-token: write
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
         with:
           fetch-depth: 1
 

.github/workflows/docker-build.yaml

@@ -12,7 +12,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       - name: Log in to GitHub Container Registry
         uses: docker/login-action@v3