Bump actions/checkout from 6.0.2 to 7.0.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 6.0.2 to 7.0.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@de0fac2...9c091bb)

---
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/main.yml

@@ -29,7 +29,7 @@ jobs:
     name: ${{ matrix.R }} ${{ matrix.os }} build
 
     steps:
-    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+    - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
       with:
         fetch-depth: 0
         ref: ${{ github.event.pull_request.head.sha }}
@@ -131,7 +131,7 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
       with:
         fetch-depth: 1