deps: update dependency org.threeten:threetenbp to v1.6.8 (#1591)

Author: renovate-bot

java-shared-dependencies/third-party-dependencies/pom.xml

@@ -23,7 +23,7 @@
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <site.installationModule>${project.artifactId}</site.installationModule>
 
-    <threeten.version>1.6.7</threeten.version>
+    <threeten.version>1.6.8</threeten.version>
     <javax.annotations.version>1.3.2</javax.annotations.version>
     <animal-sniffer.version>1.23</animal-sniffer.version>
     <opencensus.version>0.31.1</opencensus.version>