[ASTERIXDB-3541][OTH] Upgrade to Java 21

Change-Id: I70603440c83bbdc3fc60360629141b75fa512fad
Reviewed-on: https://asterix-gerrit.ics.uci.edu/c/asterixdb/+/19287
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Ian Maxon <imaxon@apache.org>
Tested-by: Ian Maxon <imaxon@apache.org>
diff --git a/asterixdb/pom.xml b/asterixdb/pom.xml
index 351c14e..aaaeb25 100644
--- a/asterixdb/pom.xml
+++ b/asterixdb/pom.xml
@@ -46,7 +46,7 @@
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <file.encoding>UTF-8</file.encoding>
     <jvm.extraargs />
-    <maven.compiler.release>17</maven.compiler.release>
+    <maven.compiler.release>21</maven.compiler.release>
     <javac.xlint.value>all</javac.xlint.value>
     <source-format.goal>format</source-format.goal>
     <source-format.skip>false</source-format.skip>
diff --git a/hyracks-fullstack/pom.xml b/hyracks-fullstack/pom.xml
index 0a9ff13..f749bbf 100644
--- a/hyracks-fullstack/pom.xml
+++ b/hyracks-fullstack/pom.xml
@@ -49,7 +49,7 @@
     <root.dir>${basedir}</root.dir>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <file.encoding>UTF-8</file.encoding>
-    <maven.compiler.release>17</maven.compiler.release>
+    <maven.compiler.release>21</maven.compiler.release>
     <javac.xlint.value>all</javac.xlint.value>
     <jvm.extraargs />
     <sonar.jacoco.reportPath>${env.PWD}/target/jacoco-merged.exec</sonar.jacoco.reportPath>