chore(deps): bump actions/checkout from 5 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 5 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v5...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -29,7 +29,7 @@ jobs:
           - name: Build
             subcommand: build --release --all-features --verbose
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Stable with rustfmt and clippy
         uses: dtolnay/rust-toolchain@stable 
         with:

.github/workflows/release-plz.yml

@@ -18,7 +18,7 @@ jobs:
     steps:
       - &checkout
         name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
           persist-credentials: true