build(deps): bump actions/checkout from 4 to 6

Bumps [actions/checkout](https://github.com/actions/checkout) from 4 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/v4...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/ci-java.yml

@@ -10,7 +10,7 @@ jobs:
   maven:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-java@v4
         with:
           distribution: temurin

.github/workflows/ci-native.yml

@@ -14,7 +14,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-latest, windows-latest]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Set up JDK (JNI)
         uses: actions/setup-java@v4
         with:

.github/workflows/ci-platform.yml

@@ -20,7 +20,7 @@ jobs:
   maven-services:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-java@v4
         with:
           distribution: temurin
@@ -41,7 +41,7 @@ jobs:
   web-ui-build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v4
         with:
           node-version: "20"

.github/workflows/ci-security.yml

@@ -20,7 +20,7 @@ jobs:
           - scan-ref: services
           - scan-ref: java
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Run Trivy filesystem scan
         uses: aquasecurity/trivy-action@0.28.0
         with:
@@ -41,7 +41,7 @@ jobs:
       run:
         working-directory: web/delivery-platform-ui
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-node@v4
         with:
           node-version: "20"

.github/workflows/release.yml

@@ -9,7 +9,7 @@ jobs:
   placeholder:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Tag pushed
         run: |
           echo "Release workflow placeholder — attach native ZIP & Maven publish in later milestone."

.github/workflows/sdk-release-checksums.yml

@@ -8,7 +8,7 @@ jobs:
   checksums:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - uses: actions/setup-java@v4
         with:
           distribution: temurin