Bump actions/setup-java from 5 to 6

Bumps [actions/setup-java](https://github.com/actions/setup-java) from 5 to 6.
- [Release notes](https://github.com/actions/setup-java/releases)
- [Commits](actions/setup-java@v5...v6)

---
updated-dependencies:
- dependency-name: actions/setup-java
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/CI.yml

@@ -41,7 +41,7 @@ jobs:
     steps:
       - uses: actions/checkout@v7
       # sbt 2 requires JDK 17+ to run
-      - uses: actions/setup-java@v5
+      - uses: actions/setup-java@v6
         with:
           distribution: 'zulu'
           java-version: '21'
@@ -62,14 +62,14 @@ jobs:
       - uses: actions/checkout@v7
       # The JDK under test: msgpack-core forks its tests onto this JDK (via
       # TEST_JAVA_HOME) so we still verify runtime behavior on each target JDK.
-      - uses: actions/setup-java@v5
+      - uses: actions/setup-java@v6
         id: target-jdk
         with:
           distribution: 'zulu'
           java-version: ${{ matrix.java }}
       # sbt 2 itself requires JDK 17+ to run, so install a fixed, newer JDK to
       # actually launch sbt. This becomes the default JDK on PATH/JAVA_HOME.
-      - uses: actions/setup-java@v5
+      - uses: actions/setup-java@v6
         with:
           distribution: 'zulu'
           java-version: '21'

.github/workflows/release.yml

@@ -18,14 +18,14 @@ jobs:
       - run: git fetch --tags -f
       # We need to compile with JDK8 for Android compatibility
       # https://github.com/msgpack/msgpack-java/issues/516
-      - uses: actions/setup-java@v5
+      - uses: actions/setup-java@v6
         id: jdk8
         with:
           java-version: 8
           distribution: adopt
       # sbt 2 itself requires JDK 17+ to run; build.sbt forks the compiler (and tests)
       # onto JDK8 via TEST_JAVA_HOME, so this becomes the default JDK on PATH/JAVA_HOME.
-      - uses: actions/setup-java@v5
+      - uses: actions/setup-java@v6
         with:
           java-version: 21
           distribution: adopt

.github/workflows/snapshot.yml

@@ -21,14 +21,14 @@ jobs:
           fetch-depth: 10000
       # Fetch all tags so that sbt-dynver can find the previous release version
       - run: git fetch --tags
-      - uses: actions/setup-java@v5
+      - uses: actions/setup-java@v6
         id: jdk11
         with:
           java-version: 11
           distribution: adopt
       # sbt 2 itself requires JDK 17+ to run; build.sbt forks the compiler onto JDK11
       # via TEST_JAVA_HOME, so this becomes the default JDK on PATH/JAVA_HOME.
-      - uses: actions/setup-java@v5
+      - uses: actions/setup-java@v6
         with:
           java-version: 21
           distribution: adopt