build(deps): bump actions/checkout from 5 to 6 (#23)

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] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/deno-ci.yaml

@@ -26,7 +26,7 @@ jobs:
 
     steps:
     - name: Checkout source
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Use Deno ${{ matrix.deno-version }}
       uses: denoland/setup-deno@v2
@@ -63,7 +63,7 @@ jobs:
 
     steps:
     - name: Checkout source
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
 
     - name: Use latest Deno
       uses: denoland/setup-deno@v2
@@ -92,7 +92,7 @@ jobs:
 
     steps:
     - uses: denoland/setup-deno@v2
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
 
     - name: Cache Deno deps
       uses: actions/cache@v4