How to create a local build that targets Java 11, when building with 17?

[Jonathan Ellis]

`./gradlew publishToMavenLocal` gives me Java 17 class files by default,
which surprises me since AFAIK 11 is still the minimum to run Lucene.

I hacked it to work by editing javac.gradle
    sourceCompatibility = JavaVersion.VERSION_11
    targetCompatibility = JavaVersion.VERSION_11

Is there a cleaner way to do this?

-- 
Jonathan Ellis
co-founder, http://www.datastax.com
@spyced