nonsensical compilation error on AUR package build

[emilyyyylime]

Installing either aur/java-langauge-server or aur/java-language-server-git fails with:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.0:compile (default-compile) on project javac-services: Fatal error compiling: error: invalid target release: 18 -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

On my setup I've been able to build the project as per https://github.com/georgewfraser/java-language-server?tab=readme-ov-file#installation-other-editors