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/publish.yml

@@ -36,7 +36,7 @@ jobs:
   publish:
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           # chartpress requires git history to set chart version and image tags
           # correctly

.github/workflows/test-chart.yaml

@@ -30,7 +30,7 @@ jobs:
   lint_shell_scripts:
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v6
         with:
           python-version: "3.11"
@@ -44,7 +44,7 @@ jobs:
   lint_and_validate_rendered_templates:
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v6
         with:
           python-version: "3.11"
@@ -77,7 +77,7 @@ jobs:
           - helm-version: v3.5.0 # minimal required version
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v6
         with:
           python-version: "3.11"
@@ -224,7 +224,7 @@ jobs:
     runs-on: ${{ matrix.os }}
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           # chartpress requires git history to set chart version and image tags
           # correctly
@@ -414,7 +414,7 @@ jobs:
     runs-on: ubuntu-24.04
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           # chartpress requires git history to set chart version and image tags
           # correctly

.github/workflows/test-docker-build.yaml

@@ -31,7 +31,7 @@ jobs:
   build_images:
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           # chartpress requires git history to set chart version and image tags
           # correctly

.github/workflows/test-docs.yaml

@@ -27,7 +27,7 @@ jobs:
   linkcheck:
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           # chartpress, used by docs/conf.py, requires git history to set
           # chart version and image tags correctly

.github/workflows/vuln-scan.yaml

@@ -51,7 +51,7 @@ jobs:
             accept_failure: false
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           # chartpress requires git history to set chart version and image tags
           # correctly

.github/workflows/watch-dependencies.yaml

@@ -79,7 +79,7 @@ jobs:
             version_patch_regexp_group_suffix: "?"
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Get values.yaml pinned tag of ${{ matrix.registry }}/${{ matrix.repository }}
         id: local
@@ -134,7 +134,7 @@ jobs:
     environment: watch-dependencies
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-python@v6
         with:
           python-version: "3.13"
@@ -206,7 +206,7 @@ jobs:
     environment: watch-dependencies
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Refreeze images/*/requirements.txt based on images/*/unfrozen/requirements.txt
         run: ci/refreeze