Configure Jitpack to just install (w/o tests)

Add install section to jitpack.yml to just build and install to local
repository. We run tests on GitHub and can even better analyze probable
problems there - so testing is not necessary on Jitpack.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: ascheman

jitpack.yml

@@ -1,3 +1,5 @@
 before_install:
   - sdk install java 17.0.10-tem
-  - sdk use java 17.0.10-tem
+  - sdk use java 17.0.10-tem
+install:
+  - ./gradlew clean build publishToMavenLocal -x test