Scope slf4j-log4j12 to test only (issue #8)

Libraries should only depend on slf4j-api and let consumers choose
their own SLF4J binding. Move slf4j-log4j12 from compile scope to
test scope so it's no longer forced on downstream users.

https://claude.ai/code/session_01KxvyXRVVZaLrgTZshvsZY6

Author: claude

pom.xml

@@ -73,6 +73,7 @@
       <groupId>org.slf4j</groupId>
       <artifactId>slf4j-log4j12</artifactId>
       <version>1.7.36</version>
+      <scope>test</scope>
     </dependency>
     <dependency>
       <groupId>org.projectlombok</groupId>