Bump to Java version 20 for Nima generator (#220)

Author: rbygrave

.github/workflows/build.yml

@@ -33,7 +33,7 @@ jobs:
         env:
           JAVA_VERSION: ${{ matrix.java_version }}
         run: |
-          if (( JAVA_VERSION < 19 ));
+          if (( JAVA_VERSION < 20 ));
           then
              mvn clean package -pl "!:avaje-http-nima-generator"
           else

http-generator-nima/pom.xml

@@ -10,9 +10,9 @@
   <artifactId>avaje-http-nima-generator</artifactId>
 
   <properties>
-    <java.release>19</java.release>
-    <maven.compiler.source>19</maven.compiler.source>
-    <maven.compiler.target>19</maven.compiler.target>
+    <java.release>20</java.release>
+    <maven.compiler.source>20</maven.compiler.source>
+    <maven.compiler.target>20</maven.compiler.target>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   </properties>