cd: Add cd workflow for spring backend

.github/workflows/cd_spring_backend.yml

@@ -0,0 +1,38 @@
+name: CD 
+
+on:
+  push:
+    branches:
+      - 'release/v[0-9]+.[0-9]+'
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up JDK 17
+        uses: actions/setup-java@v3
+        with:
+          java-version: '17'
+          distribution: 'temurin'
+          cache: maven
+
+      - name: Build with Maven
+        run: mvn -B package --file pom.xml
+
+      - name: Set up Docker buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: login to docker hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.KEI_DOCKER_USERNAME }}
+          password: ${{ secrets.KEI_DOCKER_PASSWORD }}
+
+      - name: build and push
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: ${{ secrets.KEI_DOCKER_USERNAME }}/oracle_spring_backend:${{ github.sha }}