Make jilt incremental for gradle

[iyanging]

Every time I modify just one file, Jilt triggers a full re-compilation.

gradle says:

#25 19.07 Task ':xxx:compileJava' is not up-to-date because:
#25 19.07   Input property 'stableSources' file /app/xxx/src/main/java/xxx.java has changed.
#25 19.07 Compilation mode: forking compiler
#25 19.07 Created classpath snapshot for incremental compilation in 0.07 secs.
#25 19.07 Full recompilation is required because org.jilt.JiltAnnotationProcessor is not incremental. Analysis took 0.134 secs.
#25 19.07 Compiling with toolchain '/usr/lib/jvm/jdk-23.0.1-bellsoft-x86_64'.

Please consider configuring Jilt as incremental to speed up compilation.

Refer:

• https://docs.gradle.org/current/userguide/java_plugin.html#sec:incremental_annotation_processing
• https://github.com/projectlombok/lombok/blob/9f5de53e0651142d1fa7a981f221f51a627f41d0/buildScripts/compile.ant.xml#L227

[skinny85]

Thanks for opening the issue @iyanging! I'm a little worried about all of the limitations making the processor incremental places on it, but I'll research the topic a little further.