Bump actions/checkout from 2 to 3.1.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 3.1.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2...v3.1.0)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
     container: qmkfm/qmk_cli
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3.1.0
       with:
         fetch-depth: 0