Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/build-pr.yml

@@ -13,7 +13,7 @@ jobs:
         os: [ubuntu-latest, windows-latest, macos-latest]
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Setup Java
         uses: actions/setup-java@v5
         with:

.github/workflows/main-build.yml

@@ -18,7 +18,7 @@ jobs:
         os: [ubuntu-latest, windows-latest, macos-latest]
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Validate Gradle Wrapper
         uses: gradle/actions/wrapper-validation@v5
       - name: Setup Java

.github/workflows/publishing.yaml

@@ -12,7 +12,7 @@ jobs:
       ONELITEFEATHER_MAVEN_PASSWORD: ${{ secrets.ONELITEFEATHER_MAVEN_PASSWORD }}
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Set up JDK 25
         uses: actions/setup-java@v5