chore(ci): upgrade actions to Node.js 24-compatible versions

checkout v6, setup-node v6, setup-java v5, cache v5, setup-android v4.
GitHub forces Node.js 24 for all action runners on June 2, 2026.

.github/workflows/build.yml

@@ -16,23 +16,23 @@ jobs:
       SENTRY_ORG: ${{ secrets.SENTRY_ORG }}
       SENTRY_PROJECT: ${{ secrets.SENTRY_PROJECT }}
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
 
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v6
         with:
           node-version: 20
           cache: npm
 
-      - uses: actions/setup-java@v4
+      - uses: actions/setup-java@v5
         with:
           distribution: temurin
           java-version: 17
 
       - name: Setup Android SDK
-        uses: android-actions/setup-android@v3
+        uses: android-actions/setup-android@v4
 
       - name: Cache Gradle
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: |
             ~/.gradle/caches