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/benchmark.yml

@@ -10,7 +10,7 @@ jobs:
          chmod +x bazelisk-linux-amd64
          sudo mv bazelisk-linux-amd64 /usr/local/bin/bazelisk
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
       - name: Benchmark
         run: |
           cd adventofcode/2023/day/14

.github/workflows/codeql.yml

@@ -32,7 +32,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v6
+      uses: actions/checkout@v7
 
     - name: Initialize CodeQL
       uses: github/codeql-action/init@v4

.github/workflows/nanobind.yaml

@@ -10,7 +10,7 @@ jobs:
         working-directory: .
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
         with:
           submodules: 'recursive'
       #- name: Setup tmate session

.github/workflows/nob.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       - name: Install dependencies
         run: |