ci: pull images через repo.nstart.cloud (corp Docker Hub mirror)

Runners в кластере не имеют network access к Docker Hub.
Заменили все base images:
- maven:3.9.9-eclipse-temurin-21 → repo.nstart.cloud/maven:...
- eclipse-temurin:21-jre → repo.nstart.cloud/eclipse-temurin:21-jre
- liquibase/liquibase:4.27.0 → repo.nstart.cloud/liquibase/...
- docker:27 / docker:27-dind → repo.nstart.cloud/docker:...

ordinis-read-api/Dockerfile

@@ -1,4 +1,4 @@
-FROM maven:3.9.9-eclipse-temurin-21 AS build
+FROM repo.nstart.cloud/maven:3.9.9-eclipse-temurin-21 AS build
 WORKDIR /build
 COPY pom.xml ./
 COPY ordinis-domain ./ordinis-domain
@@ -13,7 +13,7 @@ COPY ordinis-migrations ./ordinis-migrations
 COPY ordinis-read-api ./ordinis-read-api
 RUN mvn -B -pl ordinis-read-api -am package -DskipTests
 
-FROM eclipse-temurin:21-jre
+FROM repo.nstart.cloud/eclipse-temurin:21-jre
 WORKDIR /app
 COPY --from=build /build/ordinis-read-api/target/*.jar /app/app.jar
 EXPOSE 8081