dependency: Update gradle/actions action to v6

Author: renovate[bot]

.github/workflows/hangar-publish.yml

@@ -24,7 +24,7 @@ jobs:
           distribution: 'temurin'
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v5
+        uses: gradle/actions/setup-gradle@v6
 
       - name: Grant execute permission for gradlew
         run: chmod +x gradlew

.github/workflows/modrinth-publish.yml

@@ -24,7 +24,7 @@ jobs:
           distribution: 'temurin'
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v5
+        uses: gradle/actions/setup-gradle@v6
 
       - name: Grant execute permission for gradlew
         run: chmod +x gradlew