Bump actions/checkout from 5.0.0 to 6.0.0 (#110)

Bumps [actions/checkout](https://github.com/actions/checkout) from 5.0.0 to 6.0.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5.0.0...v6.0.0)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: 6.0.0
  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/push-master.yml

@@ -11,7 +11,7 @@ jobs:
   PlatformIO:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v5.0.0
+    - uses: actions/checkout@v6.0.0
 
     - name: Cache pip
       uses: actions/cache@v4.3.0