fix(deps): update dependency com.openai:openai-java to v4

Author: elastic-renovate-prod[bot]

gradle/libs.versions.toml

@@ -85,7 +85,7 @@ log4j2-slf4j = { group = "org.apache.logging.log4j", name = "log4j-slf4j2-impl",
 log4j2-core = { group = "org.apache.logging.log4j", name = "log4j-core", version.ref = "log4j2" }
 
 # Instrumented libraries
-openaiClient = "com.openai:openai-java:2.20.1"
+openaiClient = "com.openai:openai-java:4.0.0"
 
 [bundles]