Bump minimum Java version from 8 to 11

Java 8 reached end of public updates in 2019. Java 11 is the lowest
currently relevant LTS and unlocks newer dependency versions while
maintaining broad compatibility for library consumers.

https://claude.ai/code/session_01KxvyXRVVZaLrgTZshvsZY6

Author: claude

pom.xml

@@ -36,8 +36,8 @@
     </snapshotRepository>
   </distributionManagement>
   <properties>
-    <maven.compiler.source>8</maven.compiler.source>
-    <maven.compiler.target>8</maven.compiler.target>
+    <maven.compiler.source>11</maven.compiler.source>
+    <maven.compiler.target>11</maven.compiler.target>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <sonar.coverage.jacoco.xmlReportPaths>${project.build.directory}/site/code-coverage/jacoco.xml</sonar.coverage.jacoco.xmlReportPaths>
     <sonar.host.url>https://sonarcloud.io</sonar.host.url>