Build and push the backend on pr and merge

.gitea/workflows/backend.yaml

@@ -0,0 +1,31 @@
+name: Build and test backend 
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  Build-backend:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-java@v3
+      with:
+        java-version: '21'
+        distribution: 'temurin'
+    - uses: gradle/gradle-build-action@v3
+    - name: building
+      run: ./gradlew backend:build
+  Test-backend:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-java@v3
+      with:
+        java-version: '21'
+        distribution: 'temurin'
+    - uses: gradle/gradle-build-action@v3
+    - name: building
+      run: ./gradlew backend:test