CASSSIDECAR-362: duplicated caffeine version (#274)

Patch by Bernardo Botella; reviewed by Saranya Krishnakumar, Francisco Guerrero for CASSSIDECAR-362
diff --git a/gradle.properties b/gradle.properties
index 79bf9ce..ef8ed7a 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -21,7 +21,6 @@
 vertxVersion=4.5.13
 nettyVersion=4.1.118.Final
 guavaVersion=27.0.1-jre
-caffeineVersion=2.9.3
 guiceVersion=7.0.0
 slf4jVersion=2.0.17
 logbackVersion=1.5.15