Bump actions/checkout from 5 to 6 (#37)

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/test-acceptance.yaml

@@ -22,7 +22,7 @@ jobs:
     name: Acceptance tests
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Setup Bats
         uses: bats-core/bats-action@3.0.1

.github/workflows/test-chart.yaml

@@ -22,7 +22,7 @@ jobs:
     name: Chart verifier
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - uses: actions/setup-go@v6
         with:

.github/workflows/test-schema.yaml

@@ -22,7 +22,7 @@ jobs:
     name: Schema verifier
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - uses: actions/setup-go@v6
         with:

.github/workflows/test-unit.yaml

@@ -22,7 +22,7 @@ jobs:
     name: Unit tests
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Run unit tests
         run: make test-unit

.github/workflows/update.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Install Cosign
         uses: sigstore/cosign-installer@v4.0.0