build(deps): update dependency org.jacoco:jacoco-maven-plugin to v0.8.6 (#431)

Author: renovate-bot

google-cloud-spanner/pom.xml

@@ -24,7 +24,7 @@
       <plugin>
         <groupId>org.jacoco</groupId>
         <artifactId>jacoco-maven-plugin</artifactId>
-        <version>0.8.5</version>
+        <version>0.8.6</version>
         <executions>
           <execution>
             <goals>