chore(deps): bump actions/checkout in the github-actions-group group

Bumps the github-actions-group group with 1 update: [actions/checkout](https://github.com/actions/checkout).


Updates `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
  dependency-group: github-actions-group
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/radioisotopes.yaml

@@ -25,7 +25,7 @@ jobs:
 
       # 0. Initialize project sources.
       - name: Checkout repository
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       # 1. Install the Python interpreter.
       - name: Setup Python