fix(deps): update spring core to v3.2.18.release

Author: renovate[bot]

pom.xml

@@ -54,7 +54,7 @@
         <portlet-api.version>2.0</portlet-api.version>
         <resource-server.version>1.0.29</resource-server.version>
         <servlet-api.version>2.5</servlet-api.version>
-        <spring.version>3.2.15.RELEASE</spring.version>
+        <spring.version>3.2.18.RELEASE</spring.version>
         <spring-security.version>3.1.3.RELEASE</spring-security.version>
         <slf4j.version>1.7.36</slf4j.version>
     </properties>