fix(ci): use JDK 21 for Android Gradle jobs

Gradle 8.x on JDK 17 fails instrumenting bcprov-jdk18on 1.79 (Java 21
bytecode). Align CI and JoyStick publish workflow with Temurin 21.

Co-authored-by: Tim Fox <timfox@outlook.com>

Author: cursoragent

.github/workflows/build.yml

@@ -269,7 +269,7 @@ jobs:
         uses: actions/setup-java@c1e323688fd81a25caa38c78aa6df2d33d3e20d9 # v4
         with:
           distribution: "temurin"
-          java-version: "17"
+          java-version: "21"
           cache: "gradle"
           cache-dependency-path: |
             **/*.gradle*
@@ -779,7 +779,7 @@ jobs:
         uses: actions/setup-java@c1e323688fd81a25caa38c78aa6df2d33d3e20d9 # v4
         with:
           distribution: "temurin"
-          java-version: "17"
+          java-version: "21"
           cache: "gradle"
           cache-dependency-path: |
             **/*.gradle*

.github/workflows/ci.yml

@@ -267,7 +267,8 @@ jobs:
         uses: actions/setup-java@c1e323688fd81a25caa38c78aa6df2d33d3e20d9 # v4
         with:
           distribution: "temurin"
-          java-version: "17"
+          # JDK 21+: Gradle 8.x must instrument deps with Java 21 bytecode (e.g. BouncyCastle 1.79)
+          java-version: "21"
           cache: "gradle"
           cache-dependency-path: |
             **/*.gradle*

README.md

@@ -102,7 +102,7 @@ See [Development helpers](#development-helpers) and [CONTRIBUTING.md](CONTRIBUTI
 
 ## CI and workflows
 
-GitHub Actions on **`main`** / **`master`** run **[`.github/workflows/ci.yml`](.github/workflows/ci.yml)** (Linux containers, macOS, Windows, Android, optional log checks). **[`build.yml`](.github/workflows/build.yml)** (ETLBuild) runs on tagged releases, a weekly schedule, and manual dispatch. **[`snapcraft.yml`](.github/workflows/snapcraft.yml)** builds the upstream **[etlegacy-snap](https://github.com/etlegacy/etlegacy-snap)** tree after ETLBuild completes; it expects **`SNAPCRAFT_STORE_CREDENTIALS`** where publishing is desired.
+GitHub Actions on **`main`** / **`master`** run **[`.github/workflows/ci.yml`](.github/workflows/ci.yml)** (Linux containers, macOS, Windows, Android, optional log checks). The **Android** job uses **JDK 21** in CI so Gradle can handle current dependency bytecode (AGP 8.13 pulls libraries with multi-release JARs). **[`build.yml`](.github/workflows/build.yml)** (ETLBuild) runs on tagged releases, a weekly schedule, and manual dispatch. **[`snapcraft.yml`](.github/workflows/snapcraft.yml)** builds the upstream **[etlegacy-snap](https://github.com/etlegacy/etlegacy-snap)** tree after ETLBuild completes; it expects **`SNAPCRAFT_STORE_CREDENTIALS`** where publishing is desired.
 
 Forks without **`LEGACY_CI_WEBHOOK`** still get a full CI signal; the optional Discord notify step is skipped when that secret is unset.
 

app/libs/joystick/.github/workflows/build.yaml

@@ -22,9 +22,9 @@ jobs:
           fetch-tags: true
 
       - uses: actions/setup-java@c1e323688fd81a25caa38c78aa6df2d33d3e20d9 # v4
-        name: Setup Java 17
+        name: Setup Java 21
         with:
-          java-version: '17'
+          java-version: '21'
           distribution: 'temurin'
           cache: 'gradle'