chore(deps): update dependency com.google.cloud.tools:jib-maven-plugin to v3.4.0 (#1229)

Author: renovate-bot

background/pom.xml

@@ -121,7 +121,7 @@ Copyright 2019 Google LLC
       <plugin>
         <groupId>com.google.cloud.tools</groupId>
         <artifactId>jib-maven-plugin</artifactId>
-        <version>3.3.2</version>
+        <version>3.4.0</version>
         <configuration>
           <to>
             <image>gcr.io/${gcloud.appId}/background</image>

bookshelf/1-cloud-run/pom.xml

@@ -116,7 +116,7 @@ Copyright 2019 Google LLC
       <plugin>
         <groupId>com.google.cloud.tools</groupId>
         <artifactId>jib-maven-plugin</artifactId>
-        <version>3.3.2</version>
+        <version>3.4.0</version>
         <configuration>
           <from>
             <image>jetty:10.0.9-jre11</image>