fix: pom.xml to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JAVA-IOUNDERTOW-12458577
- https://snyk.io/vuln/SNYK-JAVA-CHQOSLOGBACK-13169722

Author: snyk-bot

pom.xml

@@ -29,7 +29,7 @@
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-parent</artifactId>
     <version>1.5.21.RELEASE</version>
-    <relativePath /> <!-- lookup parent from repository -->
+    <relativePath/> <!-- lookup parent from repository -->
   </parent>
 
   <licenses>
@@ -88,7 +88,7 @@
     <jgrapht-core.version>1.0.1</jgrapht-core.version>
     <datasource-proxy.version>1.4.9</datasource-proxy.version>
     <checker-qual.version>2.1.14</checker-qual.version>
-    <logstash-logback-encoder.version>4.11</logstash-logback-encoder.version>
+    <logstash-logback-encoder.version>9.0</logstash-logback-encoder.version>
     <spring-test-dbunit.version>1.3.0</spring-test-dbunit.version>
     <dbunit.version>2.5.2</dbunit.version>
     <junit-params.version>1.1.0</junit-params.version>
@@ -653,7 +653,7 @@
                     </goals>
                   </pluginExecutionFilter>
                   <action>
-                    <ignore />
+                    <ignore/>
                   </action>
                 </pluginExecution>
               </pluginExecutions>