Update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
 
       - name: Set up JDK 21
         uses: actions/setup-java@dded0888837ed1f317902acf8a20df0ad188d165 # v5

.github/workflows/gradle-wrapper-validation.yml

@@ -6,5 +6,5 @@ jobs:
     name: "Validation"
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
       - uses: gradle/actions/wrapper-validation@748248ddd2a24f49513d8f472f81c3a07d4d50e1 # v4