Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/check.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up JDK
         uses: actions/setup-java@v5
@@ -39,7 +39,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up JDK
         uses: actions/setup-java@v5
@@ -66,7 +66,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up JDK
         uses: actions/setup-java@v5
@@ -95,7 +95,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up JDK
         uses: actions/setup-java@v5
@@ -119,7 +119,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up JDK
         uses: actions/setup-java@v5
@@ -178,7 +178,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: checkout
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up JDK
         uses: actions/setup-java@v5

.github/workflows/claude-code-review.yml

@@ -27,7 +27,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 1
 

.github/workflows/claude.yml

@@ -26,7 +26,7 @@ jobs:
       actions: read # Required for Claude to read CI results on PRs
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 1