deps: update dependency org.openjdk.jmh:jmh-core to v1.25.2 (#412)

Author: renovate-bot

google-cloud-spanner/pom.xml

@@ -303,7 +303,7 @@
  <dependency>
  <groupId>org.openjdk.jmh</groupId>
  <artifactId>jmh-core</artifactId>
- <version>1.25.1</version>
+ <version>1.25.2</version>
  <scope>test</scope>
  </dependency>
  <dependency>