Fix: remove container, install Java manually

.gitea/workflows/build.yml

@@ -9,13 +9,19 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
-    container:
-      image: eclipse-temurin:21-jdk
     
     steps:
       - name: Checkout
         uses: https://gitea.com/actions/checkout@v4
 
+      - name: Setup Java 21
+        run: |
+          apt-get update && apt-get install -y wget
+          wget -q https://download.java.net/java/GA/jdk21/fd2272bbf8e04c3dbaee13770090416c/35/GPL/openjdk-21_linux-x64_bin.tar.gz
+          tar -xzf openjdk-21_linux-x64_bin.tar.gz
+          echo "JAVA_HOME=$PWD/jdk-21" >> $GITHUB_ENV
+          echo "$PWD/jdk-21/bin" >> $GITHUB_PATH
+
       - name: Grant execute permission
         run: chmod +x gradlew
 
@@ -24,9 +30,3 @@ jobs:
 
       - name: Test
         run: ./gradlew test --no-daemon
-
-      - name: Upload artifact
-        uses: https://gitea.com/actions/upload-artifact@v3
-        with:
-          name: LoChat
-          path: build/libs/LoChat-*.jar