upgrade to JKD21.

Also upgrades groovy deps, as those would no longer build.

backend.Dockerfile

@@ -7,7 +7,7 @@ COPY .git .
 RUN git describe --tags |  sed 's/^v//' > git_describe.txt
 
 # Builder
-FROM maven:3.8-openjdk-17-slim AS builder
+FROM maven:3.8-openjdk-21-slim AS builder
 
 WORKDIR /app
 

backend/pom.xml

@@ -163,10 +163,10 @@
             <version>2.9.1</version>
         </dependency>
         <dependency>
-            <groupId>org.codehaus.groovy</groupId>
-            <artifactId>groovy</artifactId>
-            <version>3.0.13</version>
-            <classifier>indy</classifier>
+            <groupId>org.apache.groovy</groupId>
+            <artifactId>groovy-all</artifactId>
+            <version>4.0.24</version>
+<!--            <classifier>indy</classifier>-->
         </dependency>
         <dependency>
             <groupId>org.apache.commons</groupId>

pom.xml

@@ -17,8 +17,8 @@
 	</parent>
 
 	<properties>
-		<java.required>17</java.required>
-		<lombok.version>1.18.24</lombok.version>
+		<java.required>21</java.required>
+		<lombok.version>1.18.36</lombok.version>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<maven.compiler.source>${java.required}</maven.compiler.source>
 		<maven.compiler.target>${java.required}</maven.compiler.target>