chore(ci): bump gradle/actions from 4 to 6

.github/workflows/coverage.yml

@@ -50,7 +50,7 @@ jobs:
           distribution: 'corretto'
 
       - name: Set up Gradle
-        uses: gradle/actions/setup-gradle@v4
+        uses: gradle/actions/setup-gradle@v6
 
       # The task deliberately lets tests fail so a flake cannot block the report. The report
       # itself carries the failure count, and gradle.yml is what actually gates on tests.

.github/workflows/cross-platform-tests.yml

@@ -43,7 +43,7 @@ jobs:
           distribution: 'corretto'
 
       - name: Set up Gradle
-        uses: gradle/actions/setup-gradle@v4
+        uses: gradle/actions/setup-gradle@v6
 
       # bash on both platforms so one command works everywhere; Git Bash ships on the Windows runner.
       - name: Run the core SDK tests

.github/workflows/dependency-security.yml

@@ -49,7 +49,7 @@ jobs:
           distribution: 'corretto'
 
       - name: Set up Gradle
-        uses: gradle/actions/setup-gradle@v4
+        uses: gradle/actions/setup-gradle@v6
 
       - name: Resolve dependencies for every module
         run: |
@@ -155,7 +155,7 @@ jobs:
           java-version: '17'
           distribution: 'corretto'
       - name: Submit resolved dependency graph to GitHub
-        uses: gradle/actions/dependency-submission@v4
+        uses: gradle/actions/dependency-submission@v6
 
   dependency-review:
     name: Review dependency changes