fix: 'No SLF4J providers were found' on examples

[vorburger]

This fixes the "No SLF4J providers were found. Defaulting to no-operation (NOP) logger implementation. See https://www.slf4j.org/codes.html#noProviders for further details." problem seen when running examples:

$ mvn compile exec:java -Dexec.mainClass="com.google.genai.examples.LiveAudioConversationAsync"

[INFO] --- exec:3.5.0:java (default-cli) @ google-genai-examples ---
Using Gemini Developer API
Microphone line opened.
Speaker line opened.
Connecting to Gemini Live API...
SLF4J(W): No SLF4J providers were found.
SLF4J(W): Defaulting to no-operation (NOP) logger implementation
SLF4J(W): See https://www.slf4j.org/codes.html#noProviders for further details.
Connected.
Microphone and speakers started. Speak now (Press Ctrl+C to exit)...
Receive stream started.

While java-genai uses JUL as its logging framework, one of its dependencies appears to use SLF4J, so doing is a good idea.

Of course, this only belongs into the example/pom.xml and NOT the root pom.xml obviously.

[vorburger]

While java-genai uses JUL as its logging framework, one of its dependencies appears to use SLF4J, so doing is a good idea.

https://github.com/TooTallNate/Java-WebSocket#logging

https://github.com/TooTallNate/Java-WebSocket/wiki/SimpleLogger-example