ci: bump actions/checkout from 5 to 6 in the checkout-and-setup group

Bumps the checkout-and-setup group with 1 update: [actions/checkout](https://github.com/actions/checkout).


Updates `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
  dependency-group: checkout-and-setup
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/a2a-tck-test.yml

@@ -30,7 +30,7 @@ jobs:
         run: |
           git config --global core.autocrlf input
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Set up JDK ${{ env.JAVA_VERSION }}
         uses: actions/setup-java@v5

.github/workflows/checks.yml

@@ -33,7 +33,7 @@ jobs:
       - name: Configure Git
         run: |
           git config --global core.autocrlf input
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up JDK ${{ env.JAVA_VERSION }}
         uses: actions/setup-java@v5
         with:
@@ -61,7 +61,7 @@ jobs:
       - name: Configure Git
         run: |
           git config --global core.autocrlf input
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       # Using setup-python on CI to install Python might be faster than with uv (official uv recommendation)
       - name: Set up Python
@@ -95,7 +95,7 @@ jobs:
       - name: Configure Git
         run: |
           git config --global core.autocrlf input
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up JDK ${{ env.JAVA_VERSION }}
         uses: actions/setup-java@v5
         with:
@@ -160,7 +160,7 @@ jobs:
       pull-requests: write
       checks: write
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: ${{ github.event.pull_request.head.sha }}  # to check out the actual pull request commit, not the merge commit
           fetch-depth: 0  # a full history is required for pull request analysis
@@ -194,7 +194,7 @@ jobs:
   knit:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: actions/setup-java@v5
         with:
           distribution: ${{ env.JAVA_DISTRIBUTION }}
@@ -222,7 +222,7 @@ jobs:
     permissions:
       contents: read
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up JDK ${{ env.JAVA_VERSION }}
         uses: actions/setup-java@v5
         with:

.github/workflows/code-agent-examples.yml

@@ -35,7 +35,7 @@ jobs:
       - name: Configure Git
         run: |
           git config --global core.autocrlf input
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up JDK ${{ env.JAVA_VERSION }}
         uses: actions/setup-java@v5
         with:

.github/workflows/demo-compose-app.yml

@@ -36,7 +36,7 @@ jobs:
       - name: Configure Git
         run: |
           git config --global core.autocrlf input
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up JDK ${{ env.JAVA_VERSION }}
         uses: actions/setup-java@v5
         with:

.github/workflows/dependency-submission.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout sources
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Setup Java
         uses: actions/setup-java@v5
         with:

.github/workflows/deploy-all-docs.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout project
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up JDK
         uses: actions/setup-java@v5
@@ -58,7 +58,7 @@ jobs:
       - name: Configure Git
         run: |
           git config --global core.autocrlf input
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       # Using setup-python on CI to install Python might be faster than with uv (official uv recommendation)
       - name: Set up Python

.github/workflows/deploy-dokka-docs.yml

@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout project
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up JDK
         uses: actions/setup-java@v5

.github/workflows/deploy-koog-ai-docs.yml

@@ -24,7 +24,7 @@ jobs:
       - name: Configure Git
         run: |
           git config --global core.autocrlf input
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       # Using setup-python on CI to install Python might be faster than with uv (official uv recommendation)
       - name: Set up Python

.github/workflows/heavy-tests.yml

@@ -71,7 +71,7 @@ jobs:
         run: |
           git config --global core.autocrlf input
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Set up JDK 17
         uses: actions/setup-java@v5

.github/workflows/ollama-tests.yml

@@ -76,7 +76,7 @@ jobs:
           echo "=== Disk space after cleanup ==="
           df -h
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: Set up JDK 17
         uses: actions/setup-java@v5
         with: