Update eclipse-temurin Docker tag to v21

Author: renovate[bot]

Dockerfile

@@ -14,7 +14,7 @@ COPY ./src /build/src
 COPY ./profiles/prod /build/profiles/prod
 RUN mvn -Pprod -DskipTests=true clean package spring-boot:repackage
 
-FROM eclipse-temurin:17.0.8_7-jre
+FROM eclipse-temurin:21.0.7_6-jre
 
 # expose server port
 EXPOSE 8080