deps: update dependency net.bytebuddy:byte-buddy-agent to v1.18.1 (#4215)

Co-authored-by: rahul2393 <irahul@google.com>

Author: renovate-bot

google-cloud-spanner/pom.xml

@@ -409,7 +409,7 @@
     <dependency>
       <groupId>net.bytebuddy</groupId>
       <artifactId>byte-buddy-agent</artifactId>
-      <version>1.17.8</version>
+      <version>1.18.1</version>
       <scope>test</scope>
     </dependency>