build(deps): bump actions/checkout from 3 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v3...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>

.github/workflows/build-multiarch.yaml

@@ -24,7 +24,7 @@ jobs:
           echo "version=${VERSION}" >> "$GITHUB_OUTPUT"
 
       - name: Checkout code
-        uses: actions/checkout@v3
+        uses: actions/checkout@v6
 
       - name: Login to DOCKER
         uses: docker/login-action@v3

.github/workflows/gen-repository-iso.yaml

@@ -40,7 +40,7 @@ jobs:
             dockerfile: dockerfile.ubuntu2404
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3
@@ -97,7 +97,7 @@ jobs:
     if: github.repository == 'kubesphere/kubekey'
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
       - shell: bash
         name: build arm harbor
         run: |

.github/workflows/golangci-lint.yaml

@@ -21,7 +21,7 @@ jobs:
     if: github.repository == 'kubesphere/kubekey'
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
@@ -44,7 +44,7 @@ jobs:
     if: github.repository == 'kubesphere/kubekey'
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
@@ -65,7 +65,7 @@ jobs:
     if: github.repository == 'kubesphere/kubekey'
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 

.github/workflows/releaser.yaml

@@ -11,7 +11,7 @@ jobs:
     if: github.repository == 'kubesphere/kubekey'
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
       - name: Prepare