deps: update dependency com.google.cloud:google-cloud-logging to v3.21.0 (#1409)

Author: renovate-bot

pom.xml

@@ -17,7 +17,7 @@
     <logback.version>1.2.13</logback.version>
     <easymock.version>5.4.0</easymock.version>
     <truth.version>1.4.4</truth.version>
-    <logging.version>3.20.6</logging.version>
+    <logging.version>3.21.0</logging.version>
     <slf4j.version>1.7.36</slf4j.version>
     <google.api-common.version>1.10.1</google.api-common.version>
   </properties>