Bump actions/checkout from 5 to 6 (#156)

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/kernel.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: 'Checkout repo'
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: 'Set up Python 3.9'
         uses: actions/setup-python@v6.0.0
       - name: 'Install dependencies'
@@ -34,7 +34,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: 'Checkout Repo'
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Build script
         id: build
@@ -88,7 +88,7 @@ jobs:
           remove-haskell: 'true'
 
       - name: 'Checkout Repo'
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Build script
         id: build
@@ -146,7 +146,7 @@ jobs:
     steps:
 
       - name: 'Checkout Repo'
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Update kernel in apt repo
         if: github.ref == 'refs/heads/Mainline-Xanmod'