Use docker registry and CI

docker/Dockerfile_app

@@ -7,10 +7,10 @@ FROM eclipse-temurin:17-jdk
 WORKDIR /tmp/compile/
 COPY ./ .
 COPY --from=0 /tmp/build/dist/ ./src/main/resources/static/
-RUN ./gradlew --no-daemon build -x test
+RUN ./gradlew --no-daemon bootJar
 
 FROM eclipse-temurin:17-jre
 WORKDIR /app
-RUN apt update && apt install -y libpcap0.8
+RUN apt update && apt install -y libpcap0.8 && rm -rf /var/lib/apt/lists/*
 COPY --from=1 /tmp/compile/build/libs/packmate-*-SNAPSHOT.jar app.jar
 EXPOSE 65000