fix: update Dockerfile to use Gradle instead of Maven

Dockerfile

@@ -1,14 +1,17 @@
 # Сборка приложения
-FROM maven:3.8.6-openjdk-11 AS build
+FROM gradle:7.6.1-jdk11 AS build
 WORKDIR /app
-COPY pom.xml .
+COPY build.gradle .
+COPY settings.gradle .
+COPY gradlew .
 COPY src ./src
-RUN mvn clean package -DskipTests
+COPY gradle ./gradle
+RUN ./gradlew clean build -x test
 
 # Запуск приложения
 FROM openjdk:11-jre-slim
 WORKDIR /app
-COPY --from=build /app/target/*.jar app.jar
+COPY --from=build /app/build/libs/*.jar app.jar
 
 # Переменные окружения для конфигурации
 ENV SPRING_DATASOURCE_URL=${DB_URL}